Todoroki Valley (等々力渓谷) is the only valley in the Tokyo area and is located in the Setagaya city ward. Most of the nature in Tokyo is artificial, but Todoroki Valley is the real deal which has been preserved throughout Tokyo’s history. The valley runs a length of 1 kilometer and offers all kind of relaxing, green scenery. Especially during summer it’s a pleasant retreat as the temperature is a lot cooler in the valley thanks to the river and all the huge trees. You will also find the Todoroki Fudo temple and a small waterfall. The valley is fairly small and you can see it all in just about a hour, but is still worth the visit as it’s a unique place to relax and cool down.
Todoroki Valley is located just outside Todoroki Station (Tokyu Oimachi Line). Free entry and opened daily. Might be closed during heavy rain, due to flooding.
Official website (in Japanese): http://www.todoroki.net/midokoro/todorokikeikoku.html