Established around 1945
This facility was constructed by the Japanese military as 1st defense line against the United Force on the northern coast of Jejudo Island and to guard Jeju East Airport (Jindeureu Airfield) and Jeju West Airport (Jeongtteureu Airfield, now Jeju International Airport). The facility consists 8 tunnel fortifications including the ‘square bracket’ form and ‘ㅡ’ form which possess two entrances and ‘Y’ form that consists of three entrances. It is one of many Japanese military facilities constructed during the Japanese Occupation and shows the tragic history of Jejudo Island which was used by Japan to resist against its enemy at the end of the Pacific War.