About the Former Taisho Forest Railway
The former Taisho forest railway ran along the Yusuhara River in Shimanto Town, Takaoka District, Kochi Prefecture, carrying timber from state forests; four of its structures built in 1944, the Sagawa Bridge, Koyagauchi Tunnel, Kakinoki Sako Bridge and Yusutanigawa Bridge, were registered as Registered Tangible Cultural Properties (structures) on March 7, 2008 (Agency for Cultural Affairs).
According to Shimanto Town, state forests along the Yusuhara River were logged heavily from the Meiji to the Showa era. In 1911 the Miura timber company of Susaki laid the first forest tramway in the Shimanto basin; the forestry office bought it in 1925, set up a timber yard at Tanono (now Taisho, Shimanto Town) and extended the line inland, creating the Taisho line along the Yusuhara River to Shimotsui. The line closed in 1966, and some of its bridges and tunnels became town roads (Shimanto Town).
Four Structures
The Sagawa Bridge, known as the Spectacles Bridge, is an 82-metre reinforced-concrete bridge of three arches, rebuilt when a dam was to flood the old track and the largest bridge of the line. The Koyagauchi Tunnel is a straight 138-metre bore through a bend of the Yusuhara River, the longest tunnel of the line (Agency for Cultural Affairs, Shimanto Town).
The Kakinoki Sako Bridge (7.0 metres) and Yusutanigawa Bridge (8.0 metres) are single semicircular concrete arches near the mouths of tributaries, with coursed stone walls on both banks. Beside the Yusutanigawa Bridge stands a stone and brick road bridge of about 1935 (Agency for Cultural Affairs, Shimanto Town).
Visiting and Location
Shimanto Town presents the four structures as components of the Cultural Landscape of the Shimanto River Basin (Taisho Oku-Shimanto Area). The Sagawa Bridge is the end point of a walking trail from Shimomichi to Shimotsui; the Koyagauchi Tunnel and Kakinoki Sako Bridge carry town roads, and the latter can be seen from the national road across the river (Shimanto Town).
The Sagawa Bridge is at Shimotsui, the Koyagauchi Tunnel and Kakinoki Sako Bridge at Koyagauchi, and the Yusutanigawa Bridge at Eshi, all in Shimanto Town. Take care with footing and traffic in the mountains.
References
- Former Taisho Forest Railway Sagawa Bridge (Database of National Cultural Properties)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00006946
- Former Taisho Forest Railway Koyagauchi Tunnel (Database of National Cultural Properties)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00006948
- Former Taisho Forest Railway Kakinoki Sako Bridge (Database of National Cultural Properties)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00006949
- Former Taisho Forest Railway Yusutanigawa Bridge (Database of National Cultural Properties)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00006950
- Cultural Landscape of the Shimanto River Basin, Taisho Oku-Shimanto Area 1 (Shimanto Town)
- https://www.town.shimanto.lg.jp/life/detail.php?hdnKey=1284
- Cultural Landscape of the Shimanto River Basin, Taisho Oku-Shimanto Area 2 (Shimanto Town)
- https://www.town.shimanto.lg.jp/life/detail.php?hdnKey=1283
Last verified: 2026.10.11
Basic Information
| Name | Former Taisho Forest Railway (Shimanto) |
|---|---|
| Location | Shimotsui, Koyagauchi and Eshi, Shimanto Town, Takaoka District, Kochi Prefecture |
| Owner | Shimanto Town |
| Designation | Registered Tangible Cultural Properties (4) |
| Coordinates | 33.24737, 132.96774 |
