A Great Keyhole Tomb at the Northern Edge
The Inarimori Kofun (稲荷森古墳) is a keyhole-shaped tomb in the Yonezawa basin at Nagaoka, Nanyo City, Yamagata Prefecture, designated a Historic Site in 1980.
The Agency for Cultural Affairs lists it under the criterion for shell mounds, settlements, tombs and similar sites.
According to the Agency, it is about 96 metres long and dated to the fifth century from its pottery and form.
The Mound
According to the Agency, it was found around 1933, recognised again through survey, and confirmed by Yamagata Prefecture's survey and excavation from 1977 to 1979. It uses one of a line of low hills running southwest, with the front mound facing south-southwest.
The rear mound is 62 metres across and about 10 metres high, built in three tiers; the front mound is 34 metres long, 32 metres wide at the end and about 5 metres high. The front is short and low compared with the rear, but the whole keeps its shape well. Traces of facing stones and pottery stands broken before the rear mound was built were found.
What to Look For
The Agency notes that the building of so large a keyhole tomb in an area at the northern edge of the tomb culture raises new questions for Kofun-period research.
The surrounding area was a settlement in the middle Kofun period, and the waist of the mound was later used for medieval burials.
Visiting the Inarimori Kofun
No official visitor information could be found. Take care not to damage the mound.
Enquiries go to the Nanyo City board of education.
Q&A
- When was the Inarimori Kofun designated?
- On 24 May 1980.
- How big is it?
- About 96 metres long, with a rear mound 62 metres across and 10 metres high.
- When was it built?
- In the fifth century, judging from its pottery and form.
- Why is it important?
- A large keyhole tomb near the northern edge of the tomb culture.
- What is distinctive about the mound?
- A three-tiered rear mound with a short, low front.
Basic Information
| Name | Inarimori Kofun (稲荷森古墳) |
|---|---|
| Location | Nagaoka, Nanyo City, Yamagata Prefecture |
| Designation | Historic Site |
| Year Designated | Designated 1980/5/24 (Showa 55) |
| Quantity | 1 tomb |
| Dimensions | About 96 metres long; rear mound 62 metres across, about 10 metres high |
| Owner | Not recorded in the Agency for Cultural Affairs database |
| Public Access | No official visitor information found |
References
- Agency for Cultural Affairs Database: Inarimori Kofun (Japanese)
- https://kunishitei.bunka.go.jp/bsys/maindetails/401/311
- Cultural Heritage Online: Inarimori Kofun (Japanese)
- https://online.bunka.go.jp/heritages/detail/201086
Last verified: 2026.09.28