The 196-km Shimanto River, whose headwaters are on Mt. Irazu in Tsuno Town, is the longest river in Shikoku and is known as “Japan’s last remaining limpid stream.” You can see the relationship between the river and local residents who live in harmony with nature amid landscapes that vary from season to season. The Agency for Cultural Affairs has designated the entire Shimanto River basin as an “Important Cultural Landscape.” Another local attraction is “Chinkabashi” – a submersible bridge without railings that sink below the water in a swollen river -- spanning the river. The 291.6-meter Sada Chinkabashi is the closest to the river’s mouth and the longest of all these bridges. A large number of tourists visit the area to see the bridge as it is the best known low-water crossing.