Pusansŏng

Pusansŏng was a Unified Silla–era Korean fortress on the mountain Busan in what is now Gyeongju, South Korea. On January 21, 1963, it was made Historic Site of South Korea No. 25.
There are conflicting records of when the fortress was built. It was possibly built during the reigns of either King Jinpyeong or King Munmu. It was used in the Goryeo period and in the Joseon period after having been repaired a number of times. Modern estimates give its circumference as. It possibly had two sets of walls. Almost all of the fortress's remains are in ruins, although a stretch of wall around in length is reportedly in decent condition. The possible sites of former buildings and villages within the fortress have been identified.