A reference site on the summit of Okanohara, an isolated hill about midway between Horinji and Hokiji in Mii, Ikaruga.
Finds & research
Cylindrical and figurative haniwa (from the Okanohara site on the eastern slope, around the early 5th century).
Official status & archaeological view
Official status
Managed by the IHA as the Tomisato reference site. Ikaruga Town's public bulletin introduces it as the mound regarded as the tomb of Prince Yamashiro-no-Oe, Prince Shotoku's son.
Attribution (jitei): the Imperial Household Agency's determination of whose tomb it manages — separate from heritage designation.
Archaeological view
A fenced round mound on the hilltop, about 30m across (Ikaruga Town). The haniwa from the Okanohara site are thought to belong to this mound. Ikaruga Town notes that these haniwa, thought to date to around the early 5th century, are older than the 7th-century death of the candidate, Prince Yamashiro-no-Oe, and names Nishinomiya Kofun in Heguri among other candidate sites for his grave.