Though there is a lot of greenery even in the heart of Tokyo, from public parks to riverbanks, there remains only one natural gorge: the Todoroki Valley in Setagaya City.

Carved by a river of spring water eroding layers of soft loam, the Todoroki Valley runs about half a mile through an upscale residential district, crossed over by the Kanpachi road at one point. The trail below traces the gentle curves of the stream, covered with a thick copse of trees on either side, a serene sylvan scenery somewhat atypical of metropolitan Tokyo.

Adjacent to the trail is the grounds of Todoroki Fudōson, a Buddhist temple whose original foundation dates back to the Heian period (794-1185). The complex contains a teahouse complete with red umbrellas, a shrine dedicated to Chigo-Daishi (Infant Kūkai), and a waterfall called Fudō-no-taki where training monks still undergo the ascetic ordeal of "waterfall meditation" to this day.

Though there exist multiple theories as to the etymology of the name Todoroki ("rumble or resounding roar"), the most popular one concerns this particular waterfall. It suggests that the “rumble” refers to the loud sound of the falling water, which must have echoed through the green valley back in the day.

Also worth mentioning is a cluster of seventh-century burial chambers preserved along the trail. Part of the larger Ebaradai Tumulus Cluster, the ancient tombs offer a fascinating glimpse into local archaeology.