Sŏngsansansŏng () 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.