One of the Kinki region's major mound groups. Yao City reports 230 surviving mounds, while the Agency for Cultural Affairs gives 224 confirmed at the time of designation. The National Historic Site covers 110 mounds centred on the Hattorigawa subgroup, rather than the whole group.
Finds & research
Korean-style pottery and miniature cooking sets suggest connections with immigrant-derived communities. A gilt-bronze mounted sword, earrings, and Sue ware are traditionally attributed to Moritayama Kofun in the Hattorigawa subgroup.
Two views on the occupant
Archaeological view
A large mound group on the slopes of Mount Takayasu in eastern Yao, built from the 6th to the first half of the 7th century and peaking in the late 6th. Taisho-era records list 565 mounds; Yao City's 2025 account says 230 survive. Nearly all are round mounds with horizontal chambers, usually three to five tatami mats in floor area, though five are nine mats or larger.
Imperial Household Agency view
This is not an Imperial Household Agency mausoleum. An area centred on the Hattorigawa subgroup, containing 110 mounds and about 63,740 square metres, was designated a National Historic Site on 10 March 2015.
Field notes
Many mounds survive among woodland and plant nurseries. Use mounds and routes open to visitors and do not enter private land.