Ishibutai Kofun was constructed in the late of Kofun period (early 7th century). Ishibutai literary means stone stage because it looks like huge stone stage. It was covered with earth, but the earth was lost and the stone chamber was appears. The historian considers this Kofun of Soga no Umako. Soga no Umako was one of the powerful family in early Japanese empire.
It is the largest Stone Grave in Japan. The entire weight of Kofun is 2,300t. The inside of the chamber is 7.7m long x 3.5m wide x 4.7m tall. It was used to be 51m square Kofun with moat.