해발 420m에 있는 계족산성은 삼국시대 때 신라의 침입을 방어하는 관문 역할을 했던 중심 산성이다.
Gyejoksanseong Fortress, located 420 meters above sea level, is a central fortress that served as a gateway of defense against the invasion of Silla during the Three Kingdoms Period.