Established around 1943
This facility, constructed under detailed plan, exhibits the largest space among tunnel fortifications in Jejudo Island. It is lattice maze-formed with 6 entrances, and was constructed to hide major military facilities such as battle command center, barrack, ammunition dump, fuel storage, aircraft repair factory, torpedo storage, and communication room in underground space against air raid of the United Force. It is a war heritage exhibiting the Japan’s invasion of Korea, and provides important site for history education.