Haman Seongsansanseong Fortress
South Korea
Sŏngsansansŏng (Hanja, RR: Seongsansanseong) was a Korean fortress on the mountain Jonamsan in what is now Haman County, South Gyeongsang Province, South Korea. The fortress has also historically gone by the name Hamansansŏng. On January 21, 1963, it was made a Historic Site of South Korea. The fortress was likely constructed by the Gaya confederacy (42–562, Korean calendar). It has two sets of stone walls.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).