Horaisan Kofun

The Horaisan Kofun is an ancient burial mound in Ota featuring the characteristic keyhole shape made of a circular section connected to a rectangular platform. The entire structure forms a large earthen mound that is now preserved within Tamagawadai Park.

The mound was built during the Kofun period between 300 and 600 CE, when powerful leaders constructed such monuments to demonstrate their authority. It belongs to an era when these burial forms were common across Japan.

The burial site shows how wealthy people of ancient times were laid to rest and what objects were placed with them for the afterlife. The shape and size of the mound reveal much about the importance and status of the person buried there.

The burial mound is accessible through Tamagawadai Park, which offers walking paths and information boards. Early morning or late afternoon are good times to visit when the site is less crowded.

The mound ranks among Tokyo's few remaining keyhole-shaped burial structures and represents a burial system that has become uncommon in this region. Its preservation provides a rare glimpse into the local burial traditions of ancient times.

Architectural style: keyhole-shaped kofun

GPS coordinates: 35.59315,139.66336

Latest update: December 14, 2025 11:20