Korean Demilitarized Zone - Incursion Tunnels

Incursion Tunnels

Since November 15, 1974, the South has discovered that four tunnels crossing the DMZ have been dug by North Korea. This is indicated by the orientation of the blasting lines within each tunnel. Upon their discovery, North Korea claimed that the tunnels were for coal mining; however, no coal has been found in the tunnels, which are dug through granite, but some of the tunnel walls have been painted black to give the appearance of anthracite.

The tunnels are believed to have been planned as a military invasion route by North Korea. Each shaft is large enough to permit the passage of an entire infantry division in one hour, though the tunnels are not wide enough for tanks or vehicles. All the tunnels run in a north-south direction and do not have branches. Following each discovery, engineering within the tunnels has become progressively more advanced. For example, the third tunnel sloped slightly upwards as it progressed southward, to prevent water stagnation. Today, visitors may visit the second, third and fourth tunnels through guided tours.