Mongchontoseong Fortress ( 서울 몽촌토성 )

It is the earthen fortifications inside the Olympic Park, which is assumed to be built between 3^rd ~ 4th century which was the time period when Baekje was starting to form a country. It is a unique rampart with a dual structure of the exterior and interior fortresses, built by utilizing the landscape of the hill areas coming down from the Namhansanseong Fortress.