| Location | Nara Pref. |
|---|---|
| Shape | Keyhole-shaped mound |
| Mound length | 318 m |
| Period | Late 6th c. |
318m mound in Kashihara City — the largest in Nara and 6th in Japan. Contains Japan's largest stone chamber (28.4m). The leading archaeological candidate for Emperor Kinmei's actual tomb.
Contains a horizontal stone chamber (yokoana-shiki sekishitsu) in the rear mound: total length ~28.4m (corridor ~17m + burial chamber ~11m long × ~2.7m wide), making it Japan's largest horizontal stone chamber. Two house-shaped sarcophagi of Aso welded tuff are known to be inside; the chamber has been entered historically and its structure is on record. Currently managed as the IHA's Unebi Ryobo Sankochi (reference site), no systematic excavation has been conducted. Identified as a strong candidate for the joint burial of Emperor Kinmei and Kitashihime (daughter of Soga no Iname), though unconfirmed. The chamber's exceptional dimensions reflect the peak of stone-chamber mound construction in the Asuka region c. late 6th–early 7th century.
Despite the IHA"s separate official designation, many scholars identify this as Emperor Kinmei"s actual tomb.