Sumida river and Sumida park

If you want to spend a day outside the Sumida park is a very nice place for it. It is very famous for the cherry blossom in the spring, but during other seasons you can enjoy it no less.
There is a bike rental service in the park – 200 Yen (for less than 24 hours), you must show your passport before renting.
In the park there is also a boat terminal from whitch you can take a boat cruise on the Sumida river and to see the side of Tokyo you have never seen. The water bus is leaving every 30 minutes, from 10:00 till 17:00 and the price is starting from 720 Yen (depends where you want to get off).
For more details check the Sumida River line on this site Tokyo Water Cruise