Ishibutai Kofun, located in Asuka Historical Park in Nara Prefecture, is one of the largest burial mounds in Japan. It is unknown whose grave it is, but it is said that it belonged to a powerful person who lived during the Asuka period. The upper surface of the stone ceiling is wide and flat, earning it the name "the stone stage" since ancient times. This ancient tomb, which looks like a collection of several megaliths, is made up of more than 30 stones stacked in a well-balanced manner. The total weight is about 2,300 tons, and the ceiling stone is especially heavy at about 77 tons. The inside of the burial mound is a stone chamber, which visitors may enter. Tourists who enter the stone chamber are amazed at the size of the stone chamber and the overwhelming beauty of the stonework. It is a historic site that shows the high level of ancient masonry techniques.