A Small Dam at the Top of the Valley
Uchihiro Sunadome (内広砂留, Uchihiro Sunadome) is a late Edo-period stone check dam in a right-bank side valley of the Dōdōgawa in Nishinakajō, Kannabe-chō, Fukuyama City, Hiroshima Prefecture, registered as a Registered Tangible Cultural Property on 3 August 2006.
According to the Agency for Cultural Affairs, it stands in the upper part of the right-bank tributary that joins the main stream above No. 6. It is 21 metres long and 3.8 metres high. It is the farthest upstream of the eight registered Dōdōgawa dams and, with Tobigasako, one of the two that guard side valleys. Its registration number is 34-0082, and it belongs to the national government through the Ministry of Land, Infrastructure, Transport and Tourism.
Why It Was Registered
The criterion is contribution to the historic landscape of the country, and the Agency values Uchihiro Sunadome as a stone dam that reaches back to the early modern period.
It is small but intricate. The walls of both wings are dry-laid without mortar, Karazumi style, and fitted as Ranzumi random masonry, while the corners are locked with Sangi-zumi, long and short faces alternating. The upper part is built in steps of Tanizumi, stones set on the diagonal. Wing, corner and top each use a different method, all within one short wall.
The other feature is that both wings project forward of the spillway. Water dropping through the spillway lands clear of the wings, so their footings are not scoured. No. 4 on the main stream uses the same idea, but at Uchihiro it belongs to the Edo-period dam. The Agency dates it to the late Edo period, between 1751 and 1829, with an extension in the Meiji era, between 1868 and 1911.
What to Look For, and Where the Sources Differ
Look for the seams: between the random walling of the wings and the quoined corners, and between those and the stepped diagonal courses on top. Along a wing no horizontal joint runs through; at the corner, long and short stones suddenly alternate with regularity. The change is clearer from an angle than head-on.
The sources disagree on some details. The Dōdōgawa Hotaru Dōkōkai gives the same 3.8-metre height as the Agency but a length of 6.2 metres, dates the construction to the mid-Edo period and says the dam was raised in the Shōwa era. This article follows the Agency's record.
The same group believes the Uchihiro and Tobigasako valleys shed so much sand that they were among the first tributaries of the Dōdōgawa to be dammed.
Visiting
Uchihiro Sunadome is an open-air river structure, free and viewable at any time without booking. Stay off the crest and spillway. No official photography restrictions are published.
According to the local group, the dam lies northwest of the toilets in Dōdō Park, so parking at the park and walking is the shortest approach. Beyond the park the path into the side valley is unimproved and the streambed is slippery after rain; wear proper shoes. Directions and parking are on the Dodogawa Sunadome group page.
- 📍 Plan Your Visit to Hiroshima
- Find tours, activities & transport passes near Uchihiro Sunadome (Stone Check Dam)
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Q&A
- Where is Uchihiro Sunadome?
- In Nishinakajō, Kannabe-chō, Fukuyama City, in the upper part of the right-bank tributary that joins the Dōdōgawa above No. 6, northwest of the toilets in Dōdō Park.
- How big is Uchihiro Sunadome?
- The Agency for Cultural Affairs records 21 metres long and 3.8 metres high. The local Dōdōgawa Hotaru Dōkōkai gives the length as 6.2 metres.
- When was Uchihiro Sunadome built?
- The Agency dates it to the late Edo period, between 1751 and 1829, with an extension in the Meiji era, between 1868 and 1911.
- What should I look for at Uchihiro Sunadome?
- Three kinds of masonry in one wall, dry random walling on the wings, quoined corners and stepped diagonal courses on top, plus wings that project forward of the spillway.
- Can I visit Uchihiro Sunadome?
- Yes, free and at any time. The side-valley path is unimproved, so wear proper shoes.
Basic Information
| Name | Uchihiro Sunadome (内広砂留) |
|---|---|
| Location | Totodani, Nishinakajo, Kannabe-cho, Fukuyama City, Hiroshima Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2006/8/3 (Heisei 18) |
| Quantity | 1 dam |
| Dimensions | Length 21 metres, height 3.8 metres |
| Owner | Government of Japan (Ministry of Land, Infrastructure, Transport and Tourism) |
| Public Access | Outdoors; open at all times, free of charge |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Uchihiro Sunadome
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00005667
- Hiroshima Prefecture Erosion Control Division: Historic Sabo Facilities, Dodogawa Sunadome (Japanese)
- https://www.sabo.pref.hiroshima.lg.jp/portal/map/AreaInfoDetail.aspx?id=187
- Dodogawa Hotaru Dokokai: The Sunadome of the Dodogawa (Japanese)
- https://dodogawa.com/sunadome.php
Last verified: 2026.09.24
