Geosite List Home Geosite River Change Ruins in Tonda-gawa River River Change Ruins in Tonda-gawa River There is a trace in the riverbed in Ichinose of Tonda-gawa River being renovated 450 years ago. The locals had called the river “an unmanageable river” before the construction. Map River Change Ruins in Tonda-gawa River 33.7151124,135.4708457,14 See in the map app