Buyeo has seven royal tombs, dating from AD 538 to 660. They're sealed for protection, but there's a re-creation of the most impressive one, which is painted with the four celestial creatures (dragon, tiger, tortoise and phoenix) that guard the compass points. There's also a small museum with a model of the oldest tomb, believed to be that of King Seong.
The tombs are on a hillside 3km east of Buyeo, a five-minute bus ride (₩1400, every 15 minutes) from Busosan-seong.