A late-period mound preserved beside Kabutoyama Kofun in Sakurabasama Historic Park, Yasu. Its lord appears to have been the first to bring an Aso pink-stone coffin to Omi — together the two mounds bear witness to the great ancient enterprise of long-distance sarcophagus transport.
Finds & research
Two coffins — monolithic Aso pink stone and composite Nijozan tuff. Silver pendant earrings, ~10,000 glass beads, 500+ iron arrowheads, spears, and horse gear.
Two views on the occupant
Archaeological view
A round mound 28m across and ~8m high, built in the early 6th century, slightly before the adjacent Kabutoyama Kofun (id:592). Its west-opening corridor chamber holds two house-shaped sarcophagi: a monolithic coffin of Aso pink stone (welded tuff from Kumamoto) for the first burial and a composite coffin of Nijozan tuff for a later one. Rich finds included silver pendant earrings, some 10,000 glass beads, 500+ iron arrowheads, spears, and horse gear (saddle fittings, stirrups, bits).
Imperial Household Agency view
Not designated by the IHA. Part of the National Historic Site "Oiwayama Kofun Group" (designated 1941 as Maruyama Kofun; consolidated into eight mounds in 1985), managed by Yasu City.
Field notes
Bus or walk from JR Yasu Station; within Sakurabasama Historic Park (9:00–17:00, closed Mondays, free). The city describes the chamber as viewable, while other sources say access is limited to special autumn openings — check with the park before visiting. See it together with Kabutoyama Kofun (id:592).