Nara Pref. Keyhole-shaped mound IHA imperial tomb

Hashihaka Kofun

Also known as: Mausoleum of Yamato Totohimomoso-hime
LocationNara Pref.
ShapeKeyhole-shaped mound
Mound length280 m
PeriodMid–late 3rd c.
DesignationImperial Mausoleum (IHA)
IHA designationIHA-managed (no public entry)

Overview

A huge early keyhole mound central to debates over the emergence of the Yamato polity. Its date and relationship to Makimuku connect it to the Yamatai and Himiko debates. A second causeway across the moat was reported in 2026.

Finds & research

The internal burial facility remains unexcavated. Investigations of the moat and perimeter have identified pottery, haniwa, and causeways. Radiocarbon and pottery chronologies permit interpretive ranges and are not treated as proof of a particular occupant.

Two views on the occupant

Archaeological view
A c.280m keyhole mound (the Agency for Cultural Affairs’ database gives c.290m) at Hashinaka, Sakurai, in the southeastern Makimuku site. Its rear circle is about 160m across, the front about 130m wide, and the mound about 30m high. Dating to the middle to latter half of the 3rd century, it is among the earliest large keyhole mounds. The internal burial facility is unexcavated and the occupant unknown. Identification as Himiko’s tomb is a major hypothesis, not an established fact.
Imperial Household Agency view
The Imperial Household Agency designates and manages it as the Oichi Tomb of Yamato Totohimomoso-hime. The designation follows the Nihon Shoki tradition; the occupant has not been archaeologically verified.

Field notes

The mound is closed as an Imperial mausoleum. View it from public roads and authorized areas, without entering the moat or managed precinct.

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Sources

桜井市 箸墓古墳桜井市 纒向遺跡第209次調査宮内庁書陵部 陵墓関係論文

Related kofun

Nishitonozuka Kofun (230m) Higashitonozuka Kofun (139m) Andonyama Kofun (242m) Shibutanimukaiyama Kofun (300m) Kurozuka Kofun (130m) Sakurai Chausuyama Kofun (207m)
← Takaidayama Kofun Nishitonozuka Kofun →