Namhansanseong

Namhansanseong, also known as Namhan Mountain Fortress, is a mountain fortress complex located on Namhan Mountain in Gwangju, Gyeonggi Province, South Korea, roughly southeast of Seoul. The site sits within Namhansanseong Provincial Park and encompasses a series of fortress walls, gates, watchtowers, bastions, and military and religious buildings that follow the natural ridgeline of the mountain. The fortress functioned as a defensive and administrative center and is an important example of Joseon-era fortification.

Construction and development of Namhansanseong date to the 17th century, with significant expansion during the Joseon dynasty. It gained particular historical prominence during the Second Manchu Invasion of Korea in 1636–37, when King Injo and much of the royal court took refuge there as Seoul was attacked and the capital fell. The fortress thereby served as a temporary palace and command center, enabling continued governance and coordination of military defenses during the siege. After the conflict, the site remained an important defensive outpost and was repaired and maintained over subsequent decades.

Today, Namhansanseong is a protected cultural heritage site and a popular destination for visitors. The fortress preserves a range of structures, including gates, walls, watchtowers, and facilities such as reservoirs and pavilions, as well as remnants of royal and religious buildings used during the siege period. It illustrates Joseon-era military engineering, provide insights into royal refuge practices, and offers hiking routes that connect historical features with the surrounding natural landscape.