A late-period mound preserved in Sakurabasama Historic Park, Yasu City, Shiga Prefecture. Its chamber still holds an intact house-shaped sarcophagus of Aso pink stone brought from Kumamoto. It sits at the foot of Mt. Oiwa.
Finds & research
Single-sleeved horizontal stone chamber (~14.2m) with an intact monolithic house-shaped sarcophagus of Aso pink stone. Finds: gold thread, lamellar armor, glass and silver beads, horse trappings, weapons.
Official status & archaeological view
Official status
Part of the National Historic Site "Oiwayama Kofun Group" (Maruyama and Kabutoyama designated 1941; six mounds added in 1985 for eight total), managed by Yasu City.
Archaeological view
A round mound built in the early-to-mid 6th century. Its chamber holds an intact monolithic house-shaped sarcophagus of Aso pink stone (Aso welded tuff from Kumamoto's Uto Peninsula, also called Makado stone), 2.6m long — among the largest in the prefecture. The Shiga Prefectural Association for Cultural Heritage notes that the reason such a huge coffin was brought all the way from the Uto Peninsula, some 800km away, is not clearly understood. The adjacent Maruyama Kofun, built slightly earlier, also holds a house-shaped sarcophagus of Aso pink stone.
Field notes
Within Sakurabasama Historic Park. Open 09:00–17:00 (last entry 16:30), free; closed Mondays, the day after holidays, and over New Year, among other closures. Check current information.