A scallop-shaped mound 84.8m long on the north bank of the Mozu River. Its rear circle is 67.6m across and 8m high, and its front section was 32m wide. Built in the late 5th century, it lost most of its moat and front section to agricultural and residential development. The rear circle and a fragment of moat at the north-east corner survive as a National Historic Site. The conserved site opened to the public on 26 April 2025.
Finds & research
A row of haniwa has been confirmed on the rear-circle terrace. Ground-penetrating radar suggests a central burial facility, but its structure and grave goods have not been confirmed.
Two views on the occupant
Archaeological view
Ground-penetrating radar in fiscal 2008 indicated a possible burial facility at the center of the rear circle. Excavation in fiscal 2011 confirmed that the rear circle had two tiers with a row of haniwa on its terrace. Details of the burial facility and grave goods remain unconfirmed.
Imperial Household Agency view
Not under Imperial Household Agency jurisdiction. It is a National Historic Site (designated in 2014 as part of the Mozu Kofun Group), protected and managed by the Sakai City Board of Education. Because it falls under a different administrative jurisdiction from the adjacent Gobyoyama Kofun (designated by the IHA as a reference site associated with Emperor Ojin), it is valuable as a mound where academic investigation and conservation work are possible.
Field notes
Conservation work was completed in fiscal 2024, and the site has been open to the public since 26 April 2025.