Japanese macaques at Jigokudani hotspring in Nagano have become notable for their winter visits to the spa.
Jigokudani Monkey Park 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.
The customs and practices observed differ depending on the hot spring. It is common practice that bathers should wash before entering the water so as not to contaminate the water (with/without soap). In many countries, like Japan, it is required to enter the hot spring with no clothes on, including swimwear.
[Nagano Prefecture‘s] mountains have made it relatively isolated, and many visitors come to Nagano for its mountain resorts and hot springs.