The mid-period link of the Oiwayama group in Yasu — bridging three centuries of chieftains from Toba (3rd c.) to Kabutoyama and Maruyama (6th c.).
Finds & research
Cylindrical, morning-glory, and figural haniwa; Sue ware. Burial unknown.
Two views on the occupant
Archaeological view
A scallop-shaped mound originally 45m+ (35m surviving; a keyhole theory exists), built in the late 5th century. Though partly quarried away, its moat is confirmed. Cylindrical, morning-glory, and figural haniwa plus Sue ware were recovered; the burial is unknown.
Imperial Household Agency view
Not designated by the IHA. Part of the National Historic Site "Oiwayama Kofun Group" (added 1985).