The largest keyhole shape tumulus which is one of the 3 largest tumuli in the world next to Pyramid of Khufu and mausoleum of the first Quin Emperor. It is 486 meters long and one of the Mozuno-mimihara-sanryo tumuli. The grave mound is 3-steps structure with 3 layers of moats, and there are more than 10 baicho (a small barrow next to a large-scale tumulus). From the moats, fukiishi (a stone covering an old tomb), clay images of human, bird, horse, dog and house, and Sue ware pot were found. From the front part, chest-shaped stone coffin was found in the pit rock chamber, along with the swords, armor and glass pots and dishes. A bronze mirror and ring-headed sword that were found in this tumulus are displayed at Boston museum in America.