This valley was made by Oya River. The depth of the valley goes to 100m high. There are many unique and interesting rocks in this valley. A picturesque location composed of a sheer precipice and a mountain stream accentuated by a series of otherworldly shaped rocks. Naruko Valley is designated by Miyagi prefecture as a place of scenic beauty in 1961.

Threes in this valley has great Koyo. Therefore, many people visit here to enjoy Autumn leaves. Koyo appears from mid October to beginning of November.