The world-famous, hot spring-loving snow monkeys in Yamanouchi, Nagano Prefecture must be Japan's most photographed wild animals. "The only place in the world where monkeys bathe in hot springs."

They live in the mountains in a valley named Jigokudani (Hell Valley). A snow monkey park (Jigokudani Yaen Koen) was established for them in 1964 where the park operator feeds the monkeys and maintains a hot spring (onsen) bath for them. Although winter (with snow) is the most popular time to see the monkeys, the park is open year round (9 am–4 pm).
This is the entrance to the trail to the snow monkey park in Yamanouchi town, Nagano Prefecture. It's about 1.6 km or a 30-min. walk (longer if you stop and take pictures).