| Location | Sakai, Osaka |
|---|---|
| Shape | Keyhole-shaped mound |
| Mound length | 146 m |
| Period | Early 5th c. |
| Designation | National Historic Site |
| World Heritage | Mozu-Furuichi Kofun Group (UNESCO) |
146m keyhole-shaped mound. In August 1955 the mound, then in private hands, was sold to a developer, and the following month a bridge for residential construction was built across its moat. Archaeologists including Koichi Mori (then a teacher at Izumiotsu High School) and Susumu Miyagawa (then a student at Osaka Dental University) called for its protection, forming the "Society to Protect Itasuke Kofun of Sakai," which ran a signature campaign and a purchase fund. They argued it was the only mound in the Mozu group other than imperial mausolea to survive complete with its moat; Sakai City bought the mound and the bridge (later splitting the cost equally with the national government), the site was provisionally designated a historic site that November, and became a National Historic Site in May 1956. Regarded as an origin of postwar citizen movements for cultural property protection, the remains of the bridge in the moat are a relic of that episode. A haniwa modeled on a keel-fronted helmet (shokaku-tsuki kabuto), excavated from the round rear mound, is the symbol mark of Sakai City's cultural property protection. The mound is also nationally known for its colony of wild tanuki (raccoon dogs). Constituent monument of the UNESCO World Heritage "Mozu-Furuichi Kofun Group" (2019).
Three-tier construction. In addition to fukiishi (facing stones) and cylindrical haniwa, a haniwa modeled on a keel-fronted helmet (shokaku-tsuki kabuto) was excavated from the round rear mound (the symbol mark of Sakai City cultural property protection). The rear circle stands 11.4m high, and the broad, short front section is distinctive. Radar survey shows the burial facility uses no stone, pointing to a clay-encased wooden coffin, but it remains unexcavated. A colony of wild tanuki (raccoon dogs) inhabits the moat, making this well known as "the kofun where tanuki live."