Third Tunnel of Aggression

Only 44 km from Seoul, the Third Tunnel was discovered in October 1978. It's 1.7 km long, 2 m high and 2 m wide. It runs through bedrock at a depth of about 73 m below ground. It's apparently designed for a surprise attack on Seoul from North Korea, and can easily accomodate a full division per hour along with their weaponry. A total of four tunnels have been discovered so far, but there is believed to be up to ten more. South Korean and US soldiers regularly drill in the DMZ in hopes of finding more. It was called a tunnel of aggression because the south considered it an act of aggression on the part of the north. They tried to play it down, saying officially that it was a coal mine shaft. They've painted black coal on the walls to help prove their statement. Actually, coal is never found deep in bedrock. You can also see the drill marks for dynamite in the walls and all the holes are pointing towards South Korea. Photos are forbidden within the tunnel and it's well guarded. The South Korean's have blocked the actual demarcation line of the DMZ in the tunnel with three concrete barricades.