A horseshoe-shaped fortress stretching from the summit of Daedeoksan Mountain at an elevation of 580 meters and embracing the Anjiraengyi Valley, Daedeoksanseong Fortress is also called “Apsansanseong Fortress.” The fortress walls were built along the dangerously high range of Daedeoksan Peak and the ridges of the foot of the mountain, stretching for a total of about three kilometers.

Now, the walls have almost completely collapsed, with only traces of piles of natural stones remaining along the mountain ridges and the more accessible slopes. It was a typical mountain fortress that maximized the use of natural rocks on the mountain, but the exact height of the original fortress wall is unknown. Pieces of ancient roof tiles and earthenware discovered scattered around the fortress site hint that it had been used from the days of Unified Silla to sometime in the Goryeo Dynasty.