Mongchon Toseong (Earthen Fortress)

Mongchon Toseong, inside Olympic Park, is an earthen fortress built by Baekje, using packed clay along the natural terrain near a tributary of the Han River.

Traces of wooden palisades were found at a stepped section of the north wall, showing the fortress was also defended with timber fencing. Built using the hills extending from Namhansanseong, it has a layered structure of outer and inner walls, and is believed to be one of early Baekje's major strongholds from the Hanseong period — the 3rd to 4th centuries, when Baekje first established itself as an ancient state — possibly the site of Hanam Wiryeseong. It's designated a national historic site.

Today it looks like a gentle grass-covered hill, making it easy to overlook as a fortress wall at first glance — but walking its ridgeline, you gradually sense the scale where natural terrain and human construction meet in striking harmony. Heading from Olympic Park's North Gate 2 toward Mongchon Toseong, you'll also find the Mongchon History Museum, where artifacts and exhibits reveal more of the fortress's story.

Set within Olympic Park, with its playgrounds and well-kept walking paths, it's a great spot to encounter Baekje history as part of a casual stroll.