In 1937, when the Chinese-Japanese War broke out, the sky over Jeju Island was filled with airplanes announcing the beginning of the war. On Jeju Island, which lies between China and Japan, the Altteureu region was one of the major military hot spots between the two countries, especially as it is located in the middle of the war.

In the middle of the fierce war, Japan prepared for a showdown on Jeju Island in March 1945 when the U.S. military invaded Iosima and launched an offensive against large cities on the mainland, including Tokyo.

The 19 vaulted hangars of heavily reinforced concrete constructed at this time contain the trials and history of the time.