Namhansanseong Fortress

A UNESCO World Heritage mountain fortress in Gwangju, Gyeonggi-do, originally built during the Baekje period and expanded in the 17th century. The 12 km fortress wall encircles Namhansan Mountain at an elevation of about 480 m. It served as an emergency capital during the Joseon Dynasty and was the site of the 1636 Manchu siege.