The Otsuka Mausoleum Reference Site, noted for its many mirrors. Official sources differ on its length and construction date.
Finds & research
The traditional assemblage includes 34 mirrors, including triangular-rimmed and straight-and-curved-pattern mirrors, beads, kuwagata stones, wheel stones, stone bracelets, gilt-bronze belt fittings, and pedestal-shaped stone objects. The IHA study questions the provenance of some objects.
Two views on the occupant
Archaeological view
A square-fronted, square-backed mound at Otsuka, Koryo, on the southeastern edge of the Umami hills. Koryo Town gives a length of about 126m, while an IHA study gives about 137m. The town’s cultural resources guide dates it to the late 4th century, whereas its study of the Suyama area places it in the middle of the Early Kofun period. A pit chamber in the rear reportedly yielded 34 mirrors, beads, bracelet-shaped stone objects, gilt-bronze belt fittings, and other goods.
Imperial Household Agency view
The Imperial Household Agency manages it as the Otsuka Mausoleum Reference Site and lists Emperor Buretsu, the 25th emperor, as a candidate occupant. The archaeological date predates his lifetime, and the occupant has not been verified.
Field notes
The mound is closed as a Mausoleum Reference Site. View it from public roads and authorized worship areas.