In the Chiyoda New Waterway, for the purpose of safely allowing the flow of the Tokachigawa River to flow down, two fishway facilities exist.
　The "Canal-type fishway," with a gentle flow, is a structure where small-sized fish whose swimming strength is weak can ascend upstream, and the "Staircase-type fishway," where the sight of fish swimming can be observed through glass, is built targeting medium-sized to large-sized fish, such as salmon and trout, etc.
　Starting with ugui, whose feature is silver-colored scales, and salmon ascending upstream to the Tokachigawa River from around the end of August, and chum salmon on whose tail fin spots can be seen, etc., in the fishway observation room "Totoro-do," you can do the act of observing the ecology of fish with the feeling of having dived into the river.