A National Historic Site known for its finely dressed horizontal stone chamber. The mound is about 40m per side according to the 1978 Kashihara Archaeological Research Institute excavation (another Asuka Village description gives about 54m).
Finds & research
A double-sleeved horizontal stone chamber of dressed stone survives. Proposed occupants include Princess Kibi, Kose no Okara no Sukune, and Empress Saimei, but none is established.
Official status & archaeological view
Official status
It was designated a National Historic Site on 11 May 1968.
Archaeological view
A square mound at Koshi, Asuka. Excavations by the Kashihara Archaeological Research Institute in 1978 confirmed it at about 40m per side, about 12m high, and two-tiered (another Asuka Village description says investigations from 1973 suggested a square mound about 54m per side). Its nearly south-facing horizontal stone chamber is built of dressed stones with polished surfaces. Asuka Village dates it to the early 7th century and calls this chamber form the Iwayayama type. Asuka Village notes that Princess Kibi, Kose no Okara no Sukune and Empress Saimei have been named as possible occupants, but that the details are unknown.
Field notes
Chamber access may change; check current Asuka Village guidance and on-site signs before entering.