Atera Valley
A valley formed along the Atera River, which rises from Mt. Sunagoya in southwestern Nagano Prefecture. The crystal-clear stream, stretching Approx. 15 km in total, is known for its outstanding transparency. Combined with the sunlight filtering through the surrounding trees, it creates the stunning emerald-green scenery known as “Atera Blue.” The water is so clear that even deep spots can look shallow, and many visitors come from outside the prefecture to see this remarkable view.
Atera Valley is seriously gorgeous! The stream is so clear it practically sparkles, and when the sunlight hits it, it turns this beautiful blue-green color. No wonder they call it “Atera Blue.”
Walking along the path by the water feels so refreshing, and it’s especially nice in summer. You can even soak your feet or play in the water. The drive feels a bit deep into the mountains, but once you arrive, it all feels totally worth it!