It is located at Yongsan (435m above sea level) at Gokran-ri, and there is a forest road on the way to Seongji (the site of the fortress).
It is a stone fortress constructed in the 3rd year of the King Taejongmuyeolwang (656), and it is Taemoe type fortress with stone at the southern part of the mild slope and soil and stone at the center on the northwest part of the stiff slope, centering on Yongsan.
There are four Munji (gate sites), Mangruji (watchtowers), Jangdaeji, two reservoir sites, and a rainbow fountain called Oweseong (outer fortress). Recently, some parts of the East gate were restored.
The total circumference of the fortress is 1,404.7m (the inner fortress) and 469.2m (the outer fortress).