The IHA-managed Ado mausoleum reference site at Tanaka, Adogawa-cho, Takashima. A tradition links it to Prince Hikoushi.
Finds & research
Haniwa fragments and river stones collected around the mound suggest haniwa and stone facing. The burial facility has not been thoroughly investigated.
Official status & archaeological view
Official status
Managed by the IHA as the Ado mausoleum reference site. A 2010 government written answer gives its archaeological name as Tanaka-Otsuka Kofun, lists the occupant's name as unknown, and gives the designation date as 21 July 1905.
Attribution (jitei): the Imperial Household Agency's determination of whose tomb it manages — separate from heritage designation.
Archaeological view
Takashima City describes a two-tiered scallop-shaped mound at the eastern edge of the Taisanjino plateau, about 72m long, with a circular part about 65m across and about 10m high. An older Shiga Prefectural Board of Education report gives about 70m. Collected haniwa suggest a mid- to late-5th-century date; stone facing and haniwa are inferred. The interior is not thoroughly investigated, and a round-mound interpretation also exists. Takashima City's public bulletin introduces it as the mound regarded as the mausoleum reference site of Prince Hikoushi, father of Emperor Keitai.
Field notes
Closed as a reference site; view from the approach. Pairs with Kamo-Inariyama↗ on a "Keitai homeland" walk.