Japanese macaques, commonly referred to as 'snow monkeys', take an open-air hot spring bath, or 'onsen' at the Jigokudani (Hell's Valley) Monkey Park in the town of Yamanouchi, Nagano prefecture.

Visitors can see the monkeys in the open-air bath every Saturday from about 1 p.m. until the end of February. (Japanese original by Kentaro Nagaoka, Kyushu News Department) ...