Southward Invasion Tunnel Investigation Team

North Korea has, over the past several decades, dug a very large number of underground tunnels south of the Demilitarized Zone in order to forcibly communize South Korea through military means.

However, in South Korea, only four such tunnels were discovered up until March 1990. After that point, no additional tunnels were officially found. Military authorities even went so far as to claim that the construction of any further long-distance tunnels was no longer possible.

Despite these claims, civilian investigators, through independent exploration, have detected the presence of many additional tunnels and have continued to disclose their findings to the public.