Chausuyama in Tennoji-ku, Osaka, is an Osaka Prefectural Historic Site traditionally described as a 5th-century keyhole-shaped kofun about 200m long. According to Osaka Prefecture, the 1986 excavation cast doubt on the theory of a 200m keyhole-shaped mound. Osaka City's guide also says the kofun interpretation is questioned. Tokugawa Ieyasu used the hill as his headquarters in the Winter Campaign of the Siege of Osaka, and Sanada Nobushige deployed here in the Summer Campaign.
Finds & research
No artifacts securely associated with a kofun have been confirmed (a tradition holds that the lid of a chest-shaped stone coffin kept at Shitennoji came from the hill). One theory identifies the adjacent the adjacent pond not as a moat but as a remnant of a canal dug in 788.
Official status & archaeological view
Official status
It was designated an Osaka Prefectural Historic Site on 31 March 1972, together with the adjacent pond.
Archaeological view
Osaka Prefecture notes that the mound fill, laid no later than the Heian period, resembles a technique often used in building kofun, so the hill may still be a kofun. Osaka City's guide records several proposed forms, including keyhole and round, and notes that no cylindrical haniwa fragments have been recognized. Another theory regards the adjacent pond as the remnant of a canal dug in 788 and the hill as its spoil.
Field notes
The hill lies in Tennoji Park and can be viewed on site.