Complex sentence: Mongchon Toseong (몽촌토성, 夢村土城) is an ancient earthen ramparts of Baekje kingdom and the part of Wiryeseong with Pungnaptoseong.
Split into simpler sentences: Mongchon Toseong (몽촌토성, 夢村土城) is an ancient earthen rampart dating from the Baekje kingdom. They are part of Wiryeseong with Pungnaptoseong.