Odusanseong Fortress

Odusanseong Fortress is a Goguryeo-period mountain fortress in Paju, Gyeonggi-do, set on Mt. Odusan at a strategic point overlooking the Imjin River where it meets the Han River — a position of historical military importance for protecting the Goguryeo kingdom's southwestern frontier. The fortress is one of Korea's older surviving fortress sites, with archaeological evidence pointing to original construction during the Goguryeo period (5th-7th centuries CE). Walking the fortress walls provides historical-and-archaeological insight along with broad open-sea-and-river views back across the Han River and Imjin River confluence. The site is also located within the broader inner Korean border zone, near the DMZ. Best paired with the Odusan Unification Observatory which is also nearby.