Mongchontoseong Earthen Fortification (
Korean: 서울 몽촌토성;
Hanja: 서울 夢村土城;
RR: Mongchontoseong) is an ancient earthen rampart dating from the
Baekje kingdom. It appears to have played the same role in defending the region as the fortifications constructed on
Mt. Acha. The fortification walls are estimated to have been about 2.7 kilometres (1.7 miles) in length and approximately 6 to 7 metres (20 to 23 feet) high. The fortifications of Mongchon Toseong had two unique features: a
palisade atop the wall and a
moat surrounding its base. They are part of
Wiryeseong with
Pungnaptoseong. It is located what is now in the
Olympic Park of
Seoul,
South Korea. During the
1988 Summer Olympics, the running section of the
modern pentathlon was held there. A number of important excavations of the site were conducted prior to the construction of the nearby Olympic Park.