It is famous for its large population of wild Japanese macaques (Macaca fuscata), more commonly referred to as snow monkeys, that go to the valley during the winter, foraging elsewhere in the national park during the warmer months. The monkeys descend from the steep cliffs and forest to sit in the warm waters of the onsen (hotsprings), and return to the security of the forests in the evenings.
Jigokudani Monkey Park is in Yamanouchi, Shimotakai District, Nagano Prefecture, Japan. It is part of the Joshinetsu Kogen National Park