New Bunker Complex Built Near Kumgang

A new unidentified bunker complex has been constructed in the village of Sangsedong-ni (상세동리) 38.696186° 127.846879°, about 14 km northwest of Kumgang and within 45 km of the DMZ. 

The site covers approximately 329 hectares (814 acres) and consists of eleven covered bunkers, a headquarters/administrative area, and ten apartment blocks. However, the bunkers don't conform to typical weapons storage structures seen in the rest of North Korea, and so the complex may have other uses such as equipment storage or even a military-industrial purpose like manufacturing/handling explosive materials.

Overview of the new Sangsedong-ni bunker complex. Google Earth, Nov. 8, 2025.

Based on AccessDPRK mapping, North Korea has over 1,500 known individual military storage locations, from simple weapons storage bunkers found at front-line units to the suspected underground nuclear warhead facility at Yongdoktong, with hundreds of other likely storage sites hidden away in lesser-known tunnels. Around 200 storage sites are large facilities covering multiple hectares. 

While sites are periodically renovated or gain expanded capacity with new bunkers being constructed, the vast majority of North Korea's storage areas are decades old. The Sangsedong-ni complex is the newest large-scale potential storage facility to be constructed. 

Residential and administrative area of the base prior to renovation. Google Earth, Sept. 29, 2022.

Prior to the construction of the bunkers, what is now the administrative area was a small, compact Korean People's Army facility with ten barracks across from a central parade ground, and little change can be noted at the base or surrounding valley on high resolution imagery from Google Earth which goes back to May 2, 2005.

The first signs of change began in May 2024 but work on the hardened structures didn't really take shape until April through July 2025. 

As seen in the image below, the probable barracks structures were removed during the site's reconstruction, but the original three administrative buildings remain in their original condition. Five unidentified new structures were also constructed to the south of the administrative site.

Residential and administrative area of the base after renovation. Google Earth, Nov. 9, 2025.

Before the site was converted to its present use, there was a collection of twenty duplex houses north of the administrative section totaling forty housing units, just inside of the base's guarded entrance. By 2025, the entrance was moved 260 meters further north and the original homes were demolished. 

To replace the duplexes, ten three-story apartment buildings were built, providing 156 individual units. The apartments are in the same 'peculiar' style as the new apartment buildings being constructed throughout the country.

This increase in living space (up from 40 units) may also be to replace the lost barracks space that existed in the administrative section of the base.

Additionally, in an adjacent valley (38.695107° 127.841137°) just outside of the base, the foundations for seven more apartment buildings were prepared. However, as of April 2026 no further construction has taken place. Whether or not these were intended to be part of the base or to provide more housing for associated personnel isn't known, but small construction projects are routinely abandoned in North Korea and I'm only mentioning this one due to its proximity to this complex. 

To the south of the residential and administrative area are eleven bunkers and support buildings. 

Map highlighting the locations of each bunker. Google Earth, Nov. 9, 2025.

The bunkers are standard rectangular concrete box forms (~30 x 7 meters) that are then covered by earth, and each have an entry structure wide enough to allow a vehicle through.

The entry structures appear to have an accessible upper floor with either windows or openings in the outer wall. The purpose of this floor is unknown but may also be part of a "camouflage, concealment, decoy" (CCD) deception scheme to misled foreign observers/analysts. 

Detail image showing a close-up of individual bunkers. Google Earth, Nov. 9, 2025.

There are no protective berms at the facility, which are often seen in locations where explosive materials or weapons are stored (or manufactured), however each of the bunkers are positioned a minimum of 70 meters apart from each other and none of the bunker openings face the opening of another bunker, which adds to the bunker's protection.

The purpose of this complex is speculative but although storage may be the easiest conclusion, military-industrial purposes can't be ruled out.

At the same time, using the structures to protect TELs or mobile artillery, particularly in light of the Ukraine and Iran wars, would make very little sense as the bunkers are in static positions, highly visible, and aren't buried deep enough to offer protection from even common missile systems like the American Tomahawk cruise missiles or the South Korean Hyunmoo-3. 

Construction around the complex is still not complete as of May 2026 but there doesn't appear to be spaces under preparation for any additional bunkers. 

I would like to thank my current Patreon supporters who help make AccessDPRK possible: Donald Pearce, David M., Dylan D., HG, Joe Bishop-Henchman, Joel Parish, John Pike, Jonathan J., Kbechs87, Russ Johnson, Squadfan, Timberwolf, and Yong H. 

--Jacob Bogle, May 20, 2026

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Bunker Busting North Korea's Nuclear Program

Although Iran hasn't demonstrated a working nuclear device, the country was believed to have had one of the most protected nuclear programs in the world with its range of air defense sites and numerous underground facilities. But following the June 2025 Israeli attacks on Iranian conventional military and nuclear infrastructure, backed up by the United States dropping fourteen "bunker buster" bombs on two key underground facilities, Iran's nuclear program has likely been knocked back by several years.

U.S. Air Force airmen inspect a GBU-57 Massive Ordinance Penetrator at Whiteman Air Base, May 2, 2023. Image: USAF 

North Korea, too, has an extensive network of underground sites to support what is the most well-developed nuclear program of the world's traditional "pariah" states. In fact, it may have more underground facilities than any modern country except (perhaps) China. And unlike Iran, North Korea has proven that it has developed nuclear devices. So, finding ways to limit or even remove Pyongyang's nuclear capabilities is something Western governments have considered for years. 

In light of the unprecedented use of the GBU-57 Massive Ordinance Penetrator (MOP) "bunker busters" against Iran's Fordow and Natanz nuclear sites, could they be used against North Korea's nuclear facilities?

A quick primer on these bombs and their capabilities. The GBU-57 MOP was the result of a US Air Force development program from 2002 to create very large conventional explosives. First tested in 2007, the first deliveries of the finalized MOP took place in 2011. 

These bombs weigh 12,304 kg (27,125 lbs) and are designed to be dropped from the B-2 Spirit 'stealth bomber' - the only aircraft in the world capable of carrying the bombs. Through the use of precision guidance systems and a "smart fuse", the bombs can be dropped on a target and detonate at a pre-determined depth. 

The exact penetrative capability of the MOP is classified but it is generally believed to be capable of penetrating 60 m (200 ft) of "ground" (what that means exactly is unspecified) and 18 m (60 ft) of reenforced concrete. However, the density of the overburden rock (limestone vs basalt) and the compressive strength of the concrete used at a target facility could dramatically impact the bomb's performance and damage.

In the case of the Iranian nuclear facilities that were bombed, parts of Fordow are estimated to lie more than 80 meters below ground, however, the bombs targeted ventilation shafts that led from the surface and may have given the bombs an easier path through the mountain into the underground facility.

So how prepared are North Korea's underground facilities to weather such an attack?

North Korea has thousands of underground sites but only a few dozen are associated with the country's nuclear and ballistic missile programs. 

However, the core of the country's nuclear infrastructure is made up of facilities that are actually out in the open.

The Yongbyon Nuclear Scientific Research Center with underground sites and tunnels highlighted.

The Yongbyon Nuclear Scientific Research Center is North Korea's crown jewel. It has two nuclear reactors, two uranium enrichment buildings, and a radiochemistry laboratory where plutonium can be produced. Yongbyon has underground sites, but the bulk of its enrichment and radioisotope production capabilities are all located above ground. What underground components do exist are relatively small and do not appear to be positioned particularly deep underground.

Newly built suspected uranium enrichment building at Yongbyon.

Even Yongbyon's newest suspected uranium enrichment building, built in 2024-2025, sits proudly in the open with a striking blue roof. A review of satellite imagery during the construction process also shows that it lacks any underground rooms and so is quite vulnerable to traditional air and missile strikes.

The Kangson Uranium Enrichment Plant.

And then there is the Kangson Uranium Enrichment Plant. Located just a few kilometers away from Pyongyang, there are no known underground parts of the plant. The use of reenforced concrete and advanced concrete formulations can, of course, make buildings much more secure. But North Korea hasn't employed the German WWII strategy of making "indestructible" buildings using hundreds of thousands of cubic yards of concrete, and they aren't known to have developed any particularly pressure resistant concrete that could deflect a direct hit from a missile. 

Thus, an adversary wouldn't need to use special ground penetrating munitions to destroy those two sites, just typical cruise or ballistic missiles. This is a critical vulnerability as destroying Yongbyon and Kangson would also prevent North Korea from producing any plutonium or from enriching enough uranium following the attacks to produce new warheads.

But there are also secret facilities that are buried beneath mountains that are rumored to hold their own centrifuge cascades and could serve as backups to Yongbyon. The two facilities that have the most supporting evidence are Kumchang-ri (40° 7'8.96"N 125° 8'28.77"E) and Hagap (40° 4'53.90"N 126°11'23.03"E). 

Kumchang-ri Suspected Nuclear Facility.

Kumchang-ri is a sprawling complex north of Kusong that was first made public in the 1990s. An American delegation was actually permitted to visit Kumchang in 1999 and in 2000 and they reported that although there were 6 miles of tunnels, the site was empty, and that its layout may not be suitable for an underground reactor facility or for running enrichment activities.

Since then, work at Kumchang has slowed dramatically. And periodic monitoring by public sources using commercial satellite imagery does not reveal any major changes that would suggest it's operational, either as a nuclear site or any other industrial purpose. 

The external grounds of Kumchang are maintained as are the surface buildings, but vehicle traffic is sparse, and there are no obvious signs of the large-scale electricity supply needed to run centrifuge cascades, no water treatment facilities, and only enough nearby housing to support a handful of workers.  

But could Kumchang be cracked open by bunker busters?

The US attack on Fordow used the facility's design against itself. The bombs were aimed at ventilation shafts that led from the surface of the mountain into the facility itself. These shafts provided more direct access to the interior and would have allowed more of the blast power from the bombs to spread instead of being absorbed by the overhead rock.

At Kumchang, there are no apparent ventilation shafts or any other access points except for the ground-level entry tunnels. This may be because construction was never completed or because they use a different technique for bringing in fresh air. Additionally, the facility is protected by up to 210 meters (690 ft.) of rock at its deepest and that means the GBU-57s would only be able to penetrate the flanks of the facility, where there is less rock protecting it.

Given what is publicly understood about the interior of Kumchang, such an attack would still likely do enough damage to render the site unusable in the short- to- medium term.

The Hagap Underground Facility.

Likewise, the Hagap Underground Facility is buried deep within a mountain and no clear visual evidence of ventilation shafts exists. Hagap's facilities are protected by between 65 and 215 meters (213-705 ft.) of rock, depending on which part of the UGF is being targeted. This would suggest that Hagap may be able to withstand an attack by GBU-57s, except for the various tunnel entrances that are at the surface. 

At least three large entrances exist, spread out along a line 800 meters (2,624 ft.) long, and work at Hagap has been ongoing for 30 years, potentially giving Hagap a more complicated interior layout than Kumchang. If Hagap is indeed a nuclear-related facility (and there are questions about this), without solid intelligence as to its design, confidently destroying the facility may require hits by six or more GBUs.

General diagram of how bunker busters work. Image: US Department of Defense.

Nuclear Assembly, Storage, and Delivery Facilities

Unlike Iran, North Korea has a proven nuclear capability. So, preventing Pyongyang from future development and also using what nuclear devices they already have is part of contingency planning in the event of an open conflict. 

Addressing the country's existing arsenal would be the most pressing issue and, I believe, the most difficult because there doesn't appear to be intelligence as to where every individual nuclear weapon is located, and North Korea does maintain numerous suitable sites for storage and missile launches. 

In terms of the GBU-57s, this poses a particular problem because, after the Iranian attacks, the US now only possesses another dozen or so of the munitions and manufacturing new ones would not be easy.

Tunnel entrances at the Yongdoktong nuclear facility before they were covered by a building in 2020.

The Yongdoktong nuclear complex (40.004721° 125.339239°) is believed to be where North Korea develops the high explosive lenses used to detonate nuclear devices and where the country assembles the final warheads. Additionally, Yongdoktong is believed to be North Korea's primary (if not sole) nuclear warhead storage facility. 

The complex does have several underground sites. The most prominent UGF (imaged above) is protected by less than 65 meters of rock for much of its area and so could be vulnerable to bunker busters. A level of uncertainty exists with attacking Yongdoktong because North Korea's nuclear command and control protocol isn't fully understood.

The country could hold all of its nuclear weapons in a single repository, only sending out warheads when personally ordered by Kim Jong Un. Or it could be the primary storage site but a small number of warheads may also be deployed to strategic missile bases around the country so that they could be quickly mated onto a missile and launched whenever ordered. These bases, 15 to 20 of them, would also require penetrative ordinances to fully destroy.

Underground entrances at the Kumchon-ni Ballistic Missile Base. The image used is from 2003 because it more clearly shows the entrances. The site looks little changed today.

The country is also dotted with thirteen hardened and underground submarine bases as well as twenty air bases with underground facilities. 

Onchon Air Base, with its distinctive T-shaped runway that is partially underground.

The Ryoho-ri submarine base at the East Sea Fleet Command.

However, the underground submarine bases would likely struggle to accommodate North Korea's only nuclear-capable ballistic missile submarine, the Hero Kim Kun Ok Class which, at 86 meters in length, is 10 meters longer than the Romeo Class which was North Korea's largest submarine class. The Hero Kim Kun Ok instead is openly berthed at the Sinpo Submarine Base; its only defense against most forms of attack would be to take to the sea.

And since North Korea doesn't have an air-based nuclear delivery system, there are no nuclear-capable bombers to hit hiding in underground air bases.

In conclusion, North Korea has a widely dispersed nuclear program. That alone makes it a more difficult problem to address militarily. But, if the United States or some other country wanted to prevent North Korea from producing additional nuclear material, that could be accomplished through the use of Tomahawk missiles or other non-bunker busting munitions. 

Although North Korea has a massive underground infrastructure, they have elected to put all of their most critical nuclear material producing facilities above ground. 

At the same time, if the United States wanted to confidently launch a strike against the country and prevent North Korea from using their present nuclear arsenal, that becomes a much different proposition.

The number of potential hardened storage sites that would likely need to be hit would deplete the entire current inventory of GBU-57 MOPs, and even then, some sites would still exist. Without exceedingly accurate and detailed intelligence, the risk of striking North Korea's nuclear infrastructure only to have them fire a nuclear-armed missile back at the United States is too great. 

The fact we haven't struck against North Korea's nuclear program suggests that the risks are indeed too great (both in terms of nuclear retaliation and the risk of an attack against Seoul) and that the intelligence is, more than likely, simply not there to adequately support such a wide-scale attack. 

In my personal view, the last chance to kinetically engage was back in the early 2000s and maybe even 1990s. Bunker busting bombs or no, now that North Korea has a proven nuclear capability and numerous places to store warheads, missiles, and other equipment, even if such weapons could destroy any individual nuclear-related site, there is currently no way to guarantee North Korea wouldn't or couldn't launch a retaliatory strike from other locations. 

I would like to thank my current Patreon supporters who help make AccessDPRK possible: Donald Pearce, David M., Dylan D, Joe Bishop-Henchman, Joel Parish, John Pike, Jonathan J., Kbechs87, Raymond Ha, Russ Johnson, Squadfan, and Yong H. 

--Jacob Bogle, 8/25/2025

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One Blue House, Two Blue House, Three...

Between 1948 and 2022, the "Blue House" (officially, Cheong Wa Dae) was the official residence of the president of South Korea. And with roots dating back to the 12th century, the complex represents both the modern South Korean state and also harkens back to when Korea was a unified peninsula and people. 

An undated photograph of the Blue House. Cropped from NamuWiki.

As the executive residence, it also features in many North Korean attempts to either overthrow the South Korean government or to invade and occupy the South. While researching for the Military Operations in Urban Terrain: Redux article, I discovered what I believe to be a previously unknown Blue House replica located between Pyongyang and Sangwon.

Since the 1960s, there have been (at least) three Blue House replicas constructed in North Korea that have been used to train DPRK special operations forces. I'd like to go into a bit more detail on the topic and have a single article that focuses solely on them. 

North Korea's Original Blue House Model

In 1967-68, members of the Korean Peoples' Army (KPA) Unit 124 trained at a specially built full-scale replica of the Blue House to prepare for their infiltration of South Korea and raid on the real Blue House in an attempt to assassinate the South Korean president. 

Google Earth image of the real Blue House.

The real Blue House is comprised of a central building that is ~66 meters long with two smaller wings and a central portico. The structure has a footprint of ~5,000 square meters and is approximately twice the size of the White House in total floor area (excluding the modern office wings). And its roof is covered in 150,000 blue tiles, thus its name. 

Its internal layout was guarded information and even today, many of the diagrams online are simplified. It's likely KPA Unit 124 only knew about a few of the main rooms and corridors, but not the full blueprints. Regardless, having a full-scale exterior model to train with, even if not entirely accurate, would have been beneficial. Afterall, they were after the president's office, not kitchen staff.  

KPA Unit 124 was headquartered in Yonsan County (38.872594° 126.255392°). Today, there aren't many military facilities in the county and no major training sites, either. However, special operations forces units don't require sprawling facilities and there is no reason that the Blue House model would still exist 57 years later, especially since the 1968 raid was a failure. 

So while I can't identify the precise location of the training grounds (nor do I know if Unit 124 still exists or was disbanded after the raid), the area around Yonsan is extremely hilly and has many valleys that could have easily held (and hidden) a special training complex for what would have been among the most secret activities ever planned and carried out by North Korea.

The 1968 raid resulted in failure and cost the lives of 30 South Korean and U.S. personnel and 29 North Korean commandos. Two of the attackers survived. 

Naturally, I would love to have more information about what this replica looked like, the training that took place, and even get a more accurate idea of where it was located. However, one survivor, Pak Jae-gyong, managed to make it back to North Korea without getting caught. He is presumed to still be alive at the age of 91. The other, Kim Shin-jo, was captured and lived out the rest of his life near Seoul. Kim died recently on April 9 at the age of 83.

2016 Scale Model

The most well-known Blue House replica was constructed in April 2016 at 38.928852° 125.924206°. It was a half-scale model of the mansion, with both wings and the portico. It even had a partially reproduced front garden and walkway.

Google Earth image of the replica after it was constructed in 2016.

At least two training exercises were carried out at the replica, the first in December 2016. These involved special operations forces parachuting down and storming the building. 

KCNA photograph from the December 12, 2016 "raid" on the Blue House scale model.

The building currently sits abandoned (within a large military exercise ground) and in a nearly totally destroyed state.

Undescribed Sangwon Model

Located at 38.899689° 125.943280°, just 3.6 km south of the 2016 model, is yet another apparent replica. To my knowledge, it was previously undescribed and I was the first person to highlight it back in March on by BlueSky account.

The nearest large town to it is Sangwon, and the replica is positioned within an elite military training complex and was constructed in 2022. It was built to 1/3rd scale and only includes the central building and portico but no wing structures. There is also a small underground entrance but that has its roots dating to 2014 and served as the entrance to a small bunker of some kind.

Comparison of the Sangwon model and real Blue House. The images aren't perfectly aligned but I think the similar features are marked adequately to establish the resemblance.

I've identified it as a scale model of the Blue House because, despite not being a complete replica, the structure's roofline is in the identical traditional Korean style, it has the same color tiles, a central portico, and central walkway like the actual building. Additionally, traditional styled buildings are not common within military bases. 

The base in which the model is located covers 178 hectares, and it is located next to another military training facility. The base was substantially renovated in 2014/15. It is also fully enclosed by perimeter fence with guard posts that were added in 2022. This is somewhat uncommon as most military bases only have partial security like an entrance gate but not a complete fence circuit. 

Also of interest near this site is a paratrooper training center two kilometers to the east.

The existence of this model underscores North Korea's continued interest in special operations against the South Korean government and raises questions about what previously unknown "decapitation strike" activities the DPRK has planned or attempted to carry out.

I would like to thank my current Patreon supporters who help make AccessDPRK possible: Donald Pearce, David M., Dylan D, Joe Bishop-Henchman, Joel Parish, John Pike, Jonathan J., Kbechs87, Raymond Ha, Russ Johnson, Squadfan, and Yong H. 

--Jacob Bogle, April 26, 2025

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Military Operations in Urban Terrain: Redux

In the earlier days of AccessDPRK, I wrote a short brief on urban warfare training centers around North Korea, otherwise known as military operations in urban terrain (MOUT). This was before the first full version of the AccessDPRK map was completed and after nine years, new discoveries have been made, and new facilities have also been constructed. 

With North Korean soldiers now in Russia, likely facing new urban combat situations in the weeks to come, I wanted to take the opportunity to revisit the topic and provide some updates to the earlier article.

KPA soldiers at an unidentified urban training center. Image: KCNA, Oct. 2024.

To review, the United States Marine Corps defines MOUT as "all military actions planned and conducted on a topographical complex and its adjacent terrain where manmade construction is the dominant feature. It includes combat in cities, which is that portion of MOUT involving house-to-house and street-by-street fighting in towns and cities".

It is believed that North Korea's primary goal during a renewed invasion of South Korea will be the capture and holding of Seoul, a city with a core population of over 9 million and a metropolitan population of 26 million. To achieve that objective, North Korean special operations forces will need to infiltrate behind the South's defensive lines at the DMZ and begin to isolate Seoul and its surrounding population centers from the rest of ROK and US forces, enabling the main body of the Korean People's Army to move in and take the city.

Indeed, according to the United States Army, the first moves of the KPA Ground Forces "will likely isolate the bypassed cities to prevent assistance from the outside or a breakout from inside the urban area."

Naturally, one needs to know how to engage in combat within populated areas to accomplish that.

Urban warfare is one of limited movement; fighting not just street-to-street but within buildings floor-to-floor, and it can require a multi-domain battle approach (land, air, and even sea) that, all too often, results in very high casualty rates. And so, getting proper training for the urban environment is essential.

North Korea's KPA MOUT centers.

In total, I've been able to identify fourteen MOUT facilities across North Korea. 

Four of them are much larger than any of the others and three are dedicated to training against specific, real-world targets: the Panmunjom "Truce Village", the ROK Armed Forces headquarters at Gyeryongdae, and there is also a mockup of the Blue House - the South Korean presidential residence until 2022. 

The other sites are smaller and fairly non-descript, but they often retain hints of the 1960s and 1970s South Korean architectural style that the larger MOUT facilities were constructed to simulate back when they were first established. 

There is also an alleged underground facility in Pyongyang that contains a scale model of a 'typical' district in Seoul complete with functional buildings and even "employees" who help the special forces personnel engage in conversation, use South Korean won, and otherwise help them become acclimatized to South Korean culture so that they can better infiltrate the South. However, its existence and location haven't been independently verified.

Main Facilities

Unsan MOUT facility divided by sections.

The largest MOUT facility (40.014045° 125.885854°) in North Korea is located in Unsan County near the village of Majang-ri. The army-level base, with all of its associated facilities, covers more than one square kilometer and includes an airborne drop tower that was built in 2014. But the MOUT part of the base covers 62 hectares and it is divided into three main sections. 

Close-up of the Unsan mock urban area.

The first section includes the base's headquarters, barracks, and associated buildings. The second section is the "urban terrain" which is 25 hectares and includes around 80 mock structures between one and six floors high. And the third section is a smaller MOUT complex that was added ca. 2014-16 and has mock satellite dishes and communication facilities.

Soe-gol MOUT facility.

The second largest MOUT facility in the country is Soe-gol in Pyongyang (39.080629° 126.092776°). Soe-gol is a large training complex with a MOUT facility, tank training areas, and other facilities. I wrote about the overall complex in 2019, following a major expansion of the base.

The MOUT facility has also undergone expansion over time. In 2005 there were twelve structures and by 2011 there were 47. There have been some small changes to the structures since 2011, but the total number remains about the same.

Pakkoryong MOUT complex.

On the outskirts of Pyongyang is another MOUT facility (38.967371° 126.105667°), about 4 km east of the village of Pakkoryong. Positioned within a small valley on the banks of the Nam River, it's fairly isolated and doesn't even have a paved road leading to it. But the Kim Jong Suk Military Academy is in Pakkoryong, and so the MOUT facility could be operated by that institution.

Established in the late 1980s, it occupies about 22 hectares and is aligned on an east-west axis. The easternmost section contains the base's headquarters and barracks. Then there's a 200-meter-long "road" with mock buildings on either side. At the west end there are eleven greenhouses that were built in 2019.

There are other structures dotted around the hillsides for a total of approximately 30 mock buildings.

Pyongsan MOUT facility.

The last of the large MOUT facilities is in Pyongsan (38.400285° 126.370334°). It's part of the KPA Army II Corps headquarters, which is nearest to the village of Wahyeon-ri (와현리) and is 57 km from the DMZ. 

The MOUT section and associated support buildings only take up 3.3 hectares and extends for 190 meters. Unlike other MOUT facilities, the Pyongsan location has actually shrunk in size over time. In 2011 it spanned over 6 hectares and was 340 meters in length. Some of the smaller structures were razed ca. 2012 and it was further reduced in size when an airborne training drop tower was constructed nearby in 2015-17.

Currently, 15+ different facades and mock buildings make up the MOUT facility.

Replica Facilities

Panmunjom is the village that used to straddle the border between North and South Korea, and it is where the 1953 Armistice Agreement was signed. It plays a highly symbolic role on the Korean Peninsula and is now where the Joint Security Area is located, which hosts inter-Korean talks, is a tourist hotspot, and has even witnessed several defections over the years as North Koreans dash across the Military Demarcation Line into the South.

Image of the real Panmunjom area.

In late 2017, a replica of Panmunjom was constructed 17 km east-northeast of the real Panmunjom, just on the other side of Kaesong. Coincidently, on Nov. 13, 2017, just a few months after the completion of the replica, a North Korean soldier defected by crossing the DMZ at the real Panmunjom.

Mock Panmunjom.

The replica facility was built on the site of a pre-existing military base and includes a fairly accurate (though, not precise) replica of the major Panmunjom buildings: the large Freedom House, the seven "blue huts" of the Armistice Commission buildings, and facades of the Peace House and Panmun-gak Administrative Headquarters. 

Security hut models and a replica DMZ post were also constructed on the site. 

The exact reason for its construction isn't known, but apart from its usefulness in training special operations forces to infiltrate or seize the site, it may have been used to help familiarize DPRK personnel with Panmunjom prior to the 2018 meetings between Kim Jong Un and South Korean president Moon Jae-in, as well as for the 2019 meeting between Kim and US President Donald Trump. 

Comparison of the real Gyeryongdae (left) and the scale model (right).

Gyeryongdae is the Republic of Korea Armed Forces Headquarters located at 36.308581° 127.218556°, about 136 km south of Seoul. The octagonal, tri-service building was constructed from 1985-89.

Given its location in the interior of the country, it's doubtful that any DPRK soldiers could make it that far before being stopped by ROK and US allied forces. Nonetheless, in 2017-18, North Korea built a 1/4th scale model of the building at a training base (39.849323° 125.681858°) just 8 km northwest of the Yongbyon Scientific Nuclear Research Center in the village of Gusan-ri.

Each of the building's eight sides are 15 meters long and the building is 40 meters in diameter. Imagery is limited, but it does look like they tried to replicate (in quarter scale) Gyeryongdae's height as well.

Unlike the Blue House replica (discussed below), I'm not aware of any military exercises at the Gusan-ri site that have been made public.

Blue House replica in 2016.

In April 2016, North Korea built a replica of the Blue House, which was the official residence of the president of South Korea between 1948 and 2022. North Korea launched a raid on the real Blue House in 1968 in an attempt to assassinate South Korean president Park Chung Hee. The attack failed but not before 59 people died (29 North Koreans, 26 South Koreans, and 4 US servicemembers). 

In preparation for the 1968 raid, members of the KPA special forces Unit 124 trained at their own replica of the building. Forty-eight years later, a new mockup was constructed on the outskirts of Pyongyang at 38.928852° 125.924206°. 

The range of hills where the replica is constructed has been used for military exercises for many years, and there is even an executive observation facility 3 km north (38.947974° 125.915933°) that was built in 1996, where the Kims and military leaders can watch the exercises when they want.

Paratroopers landing at the Blue House replica during the Dec. 12, 2016 military drill. Image: KCNA.

Since the replica's construction, North Korea has conducted at least two "raids" on the structure and publicized them through official state media. Following these drills, the structure has been left in a nearly totally destroyed state.

Additional MOUT Facilities

There are at least seven additional MOUT facilities around the country of various sizes. 

1. Haeju-Sinchang (38.134321° 125.751458°) is a set of four, multi-floor structures built in 2011 that are part of a much larger training base. It is located in the mountains 10 km north of Haeju.

2. Fifteen km northwest of the Haeju base is the Kyenam MOUT facility (38.207401° 125.604108°). The area was just a rural agricultural area until 2017-18 when various military buildings were constructed. A compact MOUT facility covering 3 hectares was also built. It had 19 small structures inside the fenced perimeter in 2018. But by 2021, the fence appears to have been removed, three of the structures were converted into real houses, and the other MOUT structures have been left to decay.

3. Near Changdo, Kangwon Province is a large training complex. An apparent MOUT section (38.641828° 127.753018°) was built in 2018-19 consisting of ten, single-story structures. A large number of barracks were also constructed at the same time, some 430 meters away, as part of renovations to the wider base.

4. A possible MOUT facility (38.553567° 124.994947°) was constructed in 2018 at a base 4 km south of the Pip'a-got submarine base. It doesn't look like the traditional mock buildings but may be collection of facades (single walls) used for targets.

5. In Pyongyang, 4.5 km northeast from Kim Jong-un's house, a set of 4 MOUT structures were built between 2009 and 2011. The coordinates are 39.148852° 125.851172°

6 and 7. The area around the Chik-tong Airfield in Koksan has two MOUT facilities. The northern one (38.723600° 126.693819°) is a modest site built in 2019. The southern facility (38.709796° 126.670334°) is larger with at least 27 structures and was constructed in 2020. Koksan has been reported to be one at which KPA soldiers bound for Ukraine have trained.

Similar MOUT training centers in countries like the United States are known to change every few years and present different urban environments that national forces may confront. After all, a city in Iraq is going to have different requirements than one in Siberia or in eastern Europe. But North Korean MOUT "villages" rarely change and are largely stuck in their design and reflect a doctrine that developed in the 1970s. 

And although the KPA's presence in Russia and Ukraine is giving North Korean soldiers the first experience of combat almost any of them will have ever seen, fighting among the towns of the vast Central Russian Plateau is only partially instructive for fighting in a dense urban environment with skyscrapers and a complex underground transit system - a city vastly changed from the Seoul of the 1970s.

Nonetheless, particularly as it pertains to small unit tactics, North Korea's MOUT facilities still offer a fertile environment for the introduction to urban combat and to the skills needed to minimize the risks associated with fighting in a populated area. 

I would like to thank my current Patreon supporters who help make AccessDPRK possible: Donald Pearce, David M., Dylan D, Joe Bishop-Henchman, Joel Parish, John Pike, Jonathan J., Kbechs87, Raymond Ha, Russ Johnson, Squadfan, and Yong H. 

--Jacob Bogle, February 26, 2025

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www.JacobBogle.com
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Nuclear Infrastructure: Yongdeok High Explosives Test Site

Deep in the western hills and mountains of North Korea lies a large fenced-off complex that occupies an entire valley. Just 7.4 km from the ancient city gate of Kusong is the Yongdeok High Explosives Test Site. (Note: it is alternatively spelled Yongdoktong.)

This facility was constructed in the 1980s and conducted numerous conventional explosive tests as part of North Korea's nuclear weapons program in the 1990s. The testing of these high explosives relates to the conventional explosive materials that make up the "lenses" within nuclear devices that compresses the fissionable core, initiating criticality and the nuclear explosion.

Kim Jong Un standing beside what has been humorously called the "disco ball", the primary stage of a nuclear device. The small circles are the locations of each polygonal, high explosive lens.

Explosive lens design and testing used to occur at the Yongbyon Nuclear Scientific Research Center but was later moved to Yongdeok once the complex became operational. As a dedicated testing and production center, Yongdeok is spread out over an area of approx. 6.3 square kilometers, with discreet facilities for the various research, design, testing, and production centers. 

It is suspected by senior US intelligence officials that Yongdeok's purpose has expanded over time, particularly since North Korea's early nuclear tests, to also become the country's primary nuclear warhead storage facility as well as its nuclear warhead assembly center.

Overview of Kusong and Yongdeok. 

There are different kinds of high explosive lens testing that can be done. These tests consist of more than just setting off a shell of explosives but involve creating an analogue core (to replicate the effects of the explosion on a real nuclear core) and recording the results in minute detail to ensure proper design and physical affects.

The simulated cores can be made up of inert, depleted uranium or even titanium. The cores are then surrounded by an explosive shell (made up of between 2 and 96 individual lenses) and the shell detonated. This compresses the metal core at temperatures so high that the core melts and reacts similarly like the real thing - just without the ensuing blast and destruction.

This kind of testing is called hydrodynamic because the core liquifies, and it has been the most common way to test this part of a nuclear device without needing to set off an actual bomb. Monitoring the implosion millisecond-by-millisecond is also energy intensive, and the entire process requires advanced technical skills.

With that said, the production sector does have a large electrical substation in the area to provide electricity and that could support modern testing (which can't be detected by outside parties). But the exact building this might occur in hasn't been publicly identified. It's also possible the tests happen in an underground test chamber.

The Yongdeok High Explosives Test Site with its main sectors highlighted.

Yongdeok can be generally divided into two main sectors, an administrative sector and a production sector which also has a residential district and is likely where testing takes place.

Yongdeok's administrative sector (2003).

Within the administrative sector are two main compounds, the administrative compound and the main security compound for Yongdeok. The administrative center will, undoubtedly, not only have offices dedicated to overseeing operations at Yongdeok but also to liaise with the multiple other nuclear research facilities throughout the country, and to develop new lenses (components, geometry, etc. to fit newer warhead designs). 

Yongdeok's production and testing area (2003).

In the production sector are the main industrial and testing areas as well as the largest housing district within Yongdeok.

There are multiple storage and handling facilities for explosive materials, assembly buildings, a large electrical substation, and other support buildings.

Yongdeok housing district (2003).

In 2003, this housing district included twelve single-story houses, eleven three-story apartment blocks, and a single-story multifamily home. These would provide space for approximately 148 families of scientists, engineers, technicians and other personnel.

Yongdeok housing district (2012).

By 2012, four additional houses were built next to the original cluster of eight homes, and a further 26 single-family houses were constructed across from the main district, bringing the total to 178 housing units in this area.

Explosives handling area (2003).

In this part of the production sector, eleven structures were protected by berms in 2003. Some are simply storage for raw materials, others for mixing and creating the final explosive mix, and still others for additional purposes.

However, the buildings within the "area of interest" box will undergo a change in the years ahead.

Explosives handling area (2012).

By 2012, the two long buildings within the area of interest had been replaced by five smaller storage structures protected by a berm. However, the activities within the long buildings may have simply been transferred to a new, single long building that was built a few meters away from the originals.

The reasons for this development likely had to do with safety or a change in the materials being handled at this site. 

Area that will eventually host an underground facility. (2003)

Yongdeok has multiple underground and hardened structures, but the most interesting and possibly largest is located at 40.030719° 125.307414°.

Two entrances are clearly visible in this 2017 image.

Sometime between 2003 and 2012, North Korea constructed this underground facility across from an unidentified set of industrial buildings. 

Normally, reviewing low-resolution LANDSAT imagery can help pinpoint a construction year as tunneling work results in large amounts of spoil (debris), which is typically dumped nearby. However, I can't find any clear signs of construction work, which means North Korea took specific care to limit what could be seen via remote observation. This probably included the use of netting to obscure the area and the removal of debris by trucks - leaving directly from the excavation site and not allowing any of it to pile up.

Underground entrance in 2021. Note, a building now covers the entrances.

The entrances are spaced ~13 meters apart and are large enough to accommodate motor vehicles. But, in 2020, the entrance was obscured by a new building. Reported on by CNN and Arms Control Wonk, the 35-meter-wide building covers the entrances but doesn't block them, and the building actually extends back into the hillside with the two entrances still very much visible. 

The purpose of the underground facility isn't publicly known. Whether it's testing, assembly, storage, or something else, the UGF continues to play an apparent central role in activities at Yongdeok.

Agricultural area (2017).

Large parts of Yongdeok are actually cultivated fields and small greenhouses, as very little cleared land in North Korea is allowed to lay fallow. The grounds next to the administrative compound are no exception. In 2017, the area held a small park but most of the land were fields. 

Agricultural area in 2023.

By 2023, a segmented garden area covering 1.2 hectares was established and three larger greenhouses were built along with two additional buildings. At the park, swimming pools were installed.

Gardens similar to this have been popping up around North Korea for the last decade or so. The food can either be grown to supplement the diets of those living in the area or grown as crops for sale (domestically or even for export), but it's most likely in this case that they're being grown to supply Yongdeok.

Probable COVID quarantine facilities (2021).

As I first hypothesized on AccessDPRK and then confirmed with NK News, North Korea built scores of COVID quarantine centers around the country. They all share the same visual signatures: external guard posts, an outer fence, and an inner wall. Sometimes they converted existing structures and other times purpose-built facilities were constructed. 

Most of these isolation centers are civilian, but some can be found at military bases. And for Yongdeok, a total of three exist, with two being built next to each other in 2021.

Detail of Site 2. 

Usually, a whole town might only have one of these secured quarantine facilities, but Yongdeok has three (the third is located at 39.993325° 125.341502°). This could be because of the national security risk posed by having a pandemic decimate the skilled population that lives and works at the site that they wanted to ensure enough treatment space was available. 

It could suggest that COVID not only hit Yongdeok but did so particularly badly, necessitating additional sites. Or maybe there's three because each one provides a larger space to patient ratio (individual rooms perhaps instead of the rows of beds at civilian facilities), so they simply needed to build more to have the required space. 

In any case, the placement of quarantine facilities at Yongdeok underscores the importance the regime places on it. Such facilities haven't been located at ballistic missile bases or even at most other military sites (including Punggye-ri). But Yongdeok has three.

In all, Yongdeok is comprised of hundreds of buildings, its own security infrastructure, and has facilities for storing and manufacturing explosive material, testing the lenses, research and development, and assembly and storage of nuclear devices. There are also enough residential units to house approximately 1,100 individuals on-site (including family members).

Yongdeok plays a critical role in North Korea's nuclear program and will for the foreseeable future. Although details of the activities at the site are unknown, satellite imagery offers us a window into one of the most secret locations in the country.

And, who knows, after Kim showed off the Kangson Uranium Enrichment Plant for the first time, maybe we'll get an official look at Yongdeok one day. 

I would like to thank my current Patreon supporters who help make all of this possible: Donald Pearce, David M., Dylan D, Joe Bishop-Henchman, Joel Parish, John Pike, Jonathan J., Kbechs87, Raymond Ha, Russ Johnson, Squadfan, and Yong H. 

--Jacob Bogle, October 26, 2024

AccessDPRK.com
www.JacobBogle.com
Twitter.com/JacobBogle