Inside the Secret North Korean Tunnels Kim Jong Un Uses for Nuclear Testing

North Korea is filled with secret tunnels. For years, satellite images have tracked the movement around these tunnels. They’ve created heightened awareness of a potential South Korea invasion. They are also used during nuclear testing. Here’s everything we know about why the tunnels are there, what they used to be for, and how they tie into North Korea’s hunger for nuclear war.

North Korean tunnels are not new

North Korean military members in uniform, with a south korea military member in fatigues.

New tunnels are constantly being discovered. | Korea Pool/Getty Images

The first underground tunnel was discovered in 1974. It was small — only about four feet high and three feet wide. Just a few months later, a second tunnel was discovered. A third was found in 1978 and one more in 1990. All of the tunnels were found in different areas, but all of them crossed over the demilitarized zone into South Korea. One tunnel was located just 32 miles from Seoul, and the South Koreans were worried that it meant trouble was to come.

Next: The tunnels are used for more than just nuclear testing. 

They were not always used for nuclear activity

Kim Jong Un sitting at a desk with binoculars.

They can be used for many reasons. | KNS/AFP/Getty Images

Many believe the tunnels were initially created for North Korea to invade the neighboring south. After a while, the thought of that threat died down as the two countries stayed out of each other’s way. However, in 2016, news.com.au reported that more tunnels were found. Awareness increased that an invasion might once again be a possibility. Some of the tunnels have the capability to move tens of thousands of troops underground and into South Korea.

Next: You won’t believe what South Korea did with the tunnels. 

… now, South Korea gives tours of them

View of the Pyongyang City and Tucheto River.

Brave tourists can get a sneak peek of the tunnels, but they can’t go too far into North Korea. | Matej Hudovernik/iStock/Getty Images

Yes, you read that right. Tourists in South Korea can actually pay to go inside one of the tunnels. Since the tunnels cross over the border, South Korea allows people to have a tour of one of them. Visitors enter through a gift shop and wear helmets to protect themselves from the low ceilings. They are taken into the underground tunnel in groups. However, access to the North Korean entrance is cut off, so the tourists can’t go very far. Some fear that tensions between the two are not low enough to be allowing these tours.

Next: The tunnels leading to South Korea are not the only ones. 

South Korea believes there are many more tunnels

Two North Korea guards in green uniforms with binoculars.

How many tunnels really exist? | Chung Sung-Jun/Getty Images

Despite having found several tunnels already, South Korea believes there are more to be discovered. One retired South Korean general said as many as 84 tunnels exist underground. The South Korean government believes there are at least 16 tunnels leading through North Korean mountains and into to the demilitarized zone.

Next: Here’s why experts believe North Korea is getting ready for another nuclear test.

Recent satellite images show increased activity around the tunnels

Kim Jong Un with binoculars.

The tunnels have seen activity recently. | STR/AFP/Getty Images.

The networks of tunnels through North Korea are also grounds for nuclear testing. 38 North, the Pyongyang watchdog, reported in January 2018 that tunneling near the nuclear test sites had stepped up. The construction means that Kim Jong Un could be getting ready for another major test. Recently, a hydrogen bomb was tested in one of the tunnels underneath a North Korean mountain. The bomb was reportedly more deadly than any of the bombs used in World War II.

Next: The tunnels are more equipped than you’d think. 

They are equipped with electricity and large enough to fit tanks

Kim Jong-Un inspecting a large tank.

Some tunnels are large enough to fit tanks and weapons. | STR/AFP/Getty Images

News.com.au reported that some of the tunnels were large enough to transport up to 30,000 troops per hour. Plus, they were wired with electricity and could even fit tanks. One of the tunnels was also equipped with a railway and rail cars. The tunnels were reinforced with concrete slabs. The high-function tunnels are able to hold North Koreans looking to invade the south or can be used to for detonation of hydrogen bombs.

Next: Here’s how dangerous these tunnels actually are. 

The tunnels have killed North Koreans

Kim Jong Un inspects a weapon.

Tests in the tunnels have gone wrong in the past. | STR/AFP/Getty Images.

The tunnels are also responsible for the deaths of many North Korean soldiers. The hydrogen bomb tested below the mountain left the mountain very unstable. Landslides and seismic aftershocks caused a tunnel to collapse on 100 North Korean soldiers. Japan reported that an additional 100 soldiers went in to save them and were also killed. 38 North said the mountains were likely suffering from “tired mountain syndrome” which occurs when surrounding rock becomes extremely fragile and permeable.

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