It is the fortress of the Joseon Dynasty (1392-1910) to protect Hanyang, the capital of Joseon Dynasty, with Bukhansanseong Fortress. This fortress has a long history dating back to the Silla Dynasty (57 B.C.-A.D.935) when a wall, Jujangseong, assumed as the present Namhansanseong Fortress, was built here during the reign of Silla's King Munmu (661-681). A sweeping renovation was begun in 1624, the second year of the reign of King Injo (1623-49), when motivated by following the threat of Aggression by the Latter Jin, the court ordered Yi So, a garrison commander, to renovate the wall. King Injo took shelter at here in 1636 when the Manchurians invaded the Joseon Dynasty. Peace was negotiated with the invading Manchurians here in 1637, the 15th year of the reign of King Injo. Since then, the renovations were had been continued. There were four major gates for each direction, only the one in the West remains. Other existing facilities include the shrine, the hall, pavilions, and a shrine to General Yi So, as well as several forts and some military guard posts. A lot of relics of the early Baekje Dynasty (18B.C.-A.D.668) were found here, so it is said to be a palace of King Onjo of Baekje. Namhansanseong Fortress is the best facilitated one in Korea.