Jigokudani Monkey Park is a famous hot spring area near Nagano, Japan. The name Jigokudani (meaning “Hell’s Valley”), is due to steam and boiling water that bubbles out the frozen ground, surrounded by steep cliffs and formidably cold and hostile forests.

It is famous for its large population of wild Snow Monkeys that go to the valley during the winter when snow covers the park. The monkeys descend from the steep cliffs and forest to sit in the warm waters of the onsen (hot springs), and return to the security of the forests in the evenings.