Imashirozuka Kofun

The largest ancient kofun tomb in the Yodo River basin, the 6th-century Imashirozuka Kofun is unique in several aspects. It is likely one of the only ancient keyhole mound tombs of a Japanese emperor which one can actually walk around and climb. This is because when it was identified as the probable tomb of Emperor Keitai, the Imperial Household Agency had already assumed that he was buried in another location. As such, they declined to award protection to the tomb, which today remains under the stewardship of the local government.

For many years until its excavation and conversion into a park, Imashirozuka Kofun was in a very neglected state. Its primary mound has partially collapsed, which was thought to be because the warlord Oda Nobunaga built a castle on it in the 16th century. In reality, the collapse occurred because of an earthquake in 1596, according to archaeologists.

Commonly found among kofun tombs of the 3rd through 6th centuries are haniwa, terracotta figures used as funerary objects. Cylindrical haniwa were used to support the kofun mounds, and haniwa shaped as people, objects, animals, or houses were placed on top of or around the mounds. They were likely supposed to play a role in protecting or housing spirits of the deceased. Imashirozuka Kofun is unique among such sites in having an actual reconstruction of such a ritual precinct of haniwa, similar to the army of terracotta warriors in front of Emperor Qin Shi Huang's tomb in China.