The largest keyhole mound in Yao City and in central Kawachi (160m). Early-5th-century construction with three-tiered mound, stone covering, and haniwa rows. National Historic Site. The name "Shionji Yama" derives from a temple once located here. As a large-scale early-5th-century mound, it is an important indicator of central Kawachi's power contemporaneous with the Furuichi and Mozu groups.
Finds & research
Multiple excavations by Yao City and Osaka Prefecture boards of education since a 1976 trial excavation have progressively revealed mound structure, stone paving arrangement, and haniwa layouts. Finds include house-shaped, canopy-shaped, and enclosure-shaped haniwa — a rich variety vividly reflecting early-5th-century funerary ritual practices. The adjacent "Shionji Yama Kofun Learning Center" displays excavated haniwa and excavation records.
Two views on the occupant
Archaeological view
Occupant unknown. The largest keyhole mound in central Kawachi (central Osaka Prefecture), dated to the early 5th century (c. 400–420s). Three-tiered construction: 160m long, rear circle 93m diameter and 14m high, front section 107m wide and 12m high. Stone covering and cylindrical haniwa rows have been confirmed across the entire surface. Excavated haniwa include house-shaped, canopy-shaped, and enclosure-shaped figures, vividly reflecting funerary ritual practices. The occupant is presumed to have been a powerful local chief of central Kawachi with ties to the Yamato polity.
Imperial Household Agency view
Not managed by the IHA. National historic site, administered by Yao City as the publicly accessible "Shionji Yama Kofun Park." Not designated as an imperial or reference site, enabling full archaeological excavation. Multiple excavation campaigns since a 1976 trial excavation have progressively revealed details of the mound, haniwa, and stone chamber.
Field notes
Freely open to the public as "Shionji Yama Kofun Park"; one of the few kofun in Osaka where visitors can climb to the summit, popular with families. The adjacent "Shionji Yama Kofun Learning Center" displays excavated haniwa and excavation records. Replica haniwa are arranged within the park. Nearest stations: JR Shiki or Kintetsu Kyuhojiguchi, both ~10 min walk. Parking available. Free admission.