Achasan Fortress, Seoul

Mountain fortress and outpost sites from the Three Kingdoms period located along the ridge of Achasan Mountain in Gwangjin-gu, Seoul, which was a military stronghold overlooking the Hangang River. Outpost sites built during the period when Goguryeo contended with Baekje and Silla over the Hangang River basin are confirmed at several places along the ridge. The excavated pottery and weapons show Goguryeo's military activities of the time. It is a place that vividly conveys the front line of the struggle for the Hangang River and the scene of the contention among the Three Kingdoms.