Tanba's largest keyhole mound, lying in the eastern Sasayama basin. Meiji-era drawings of its buried armory conjure a warrior king. Managed by the IHA as a reference site, the mound itself is off-limits, but the view across the water-filled moat is imposing.
Finds & research
Pit-style chamber with an unopened chest-style sarcophagus. The 1896 drawings record 34 swords, 8 blades, 4 helmets, 5 cuirasses, and 107 arrowheads; a 2004 survey confirmed haniwa and Sue ware.
Two views on the occupant
Archaeological view
A keyhole mound 140m long (perhaps 158m restored, as the skirt is submerged) — the largest in Tanba and second in Hyogo — with a shield-shaped moat and outer belt. Built in the mid-5th century. An 1896 dig by villagers revealed a pit-style chamber holding a chest-style sarcophagus and a huge armory: 34 swords, 8 blades, 4 helmets, 5 cuirasses, 107 arrowheads (recorded in drawings; the coffin was reburied unopened). Archaeologists see a paramount Tanba chieftain; the IHA's candidate is generally thought too early.
Imperial Household Agency view
Managed by the IHA as the "Kumobe Ryobo Sankochi" (reference site; one source gives 1900 as the designation year). The candidate occupant is Tanba-no-Michinushi-no-mikoto, a great-grandson of an early emperor. As a reference site the mound is closed; viewing is from the perimeter.
Field notes
About 5 min on foot from the Higashi-Honjo bus stop (no parking). The mound and moat are closed; view from the outer path. Some records and drawings are kept at the Kyoto University Museum.