Shimanto River — Sada submersible bridge (四万十川・佐田沈下橋) 四万十川・佐田沈下橋

291.6 metres with no railings: the longest bridge the river swallows when it floods.

The river was called the Watari-gawa until 1994, when its name was changed to Shimanto-gawa: the first revision of a river's name under the Japanese river law. It appears in three national lists: 100 famous waters, 100 remote places, 100 headwater forests.

Kochi