The Namhansan-song Fortress was rebuilt several times after King Onjo of
Paekche Kingdom first built it in earth to prevent the invasions from
outside forces. In 1608, during King Kwanghae's rule, the fortress was
rebuilt with the mobilization of monk soldiers from all across Choson.
King Injo escaped to the Namhansan-song Fortress with 12,000 soldiers when
the Ching Dynasty invaded Choson in 1636 and faced the enemy for 45 days
but finally surrended.