Shiromaru Dam and Fish Ladder
The Shiromaru Dam is located in the town of Okutama, about 2 hours west of Shinjuku on the JR Ome Line.
The dam, relatively small in size, generates electricity for use by the Toei subway and trams. The main point of interest is the fish ladder which allows ayu sweetfish and yamame (landlocked salmon) to safely move upstream.
The most striking structure is the spiral staircase that leads down 30 meters to the ladder. Its unique appearance has gotten increased attention in the local media and even used in a music video for the idol group Sakurazaka 46.
Combine the visit with a walk along the scenic Hatonosu Gorge. The area is of particular beauty when the fresh leaves come out in late April or for the autumn colors (usually mid November).
Note that the fish ladder opens to the public only on weekends and holidays between April and November. From mid July to the end of August (the school holiday period) it will open daily. Hours are from 10am-4pm with last entry at 3:30pm.
The entry to the facility will be through the building with the beige colored walls. Entry is free and you go down the spiral staircase that the place is known for.
Note that you will not be permitted to go up the same spiral staircase as there is a separate set of stairs for coming back up.
Additional Tips for your visit...
There is parking space for a few cars near the site.
If you are visiting on foot, the dam is about midway between JR Hatonosu and Shiromaru Stations. It is advised to cross the Tama River from a nearby bridge and walk the side to the south of the river (You will see a green dotted line on Google Maps for parts of this trail). Route 411 that runs north of the river has no sidewalk and is very unsafe.
Both the Hatonosu and Shiromaru stations are unstaffed and without a ticket machine. There is a machine for tapping in/out with your SUICA or PASMO but ensure you have stored enough money beforehand.
