If you’ve ever watched a nature documentary about Japan, there's a good chance you’ve seen the famous monkeys of this park chilling out in volcanic hot springs, looking utterly blissed out. To see these cheery Japanese macaques for yourself, you’ll need to head to Jigokudani Valley by the town of Yamanouichi.
Unlike their fully wild cousins, the monkeys of the park grew up with plenty of human interaction, so they’re not shy by any means. For the most part, they just about their daily business of socializing, grooming, and bathing without paying the tourists any mind (unless they bring out some fruit or a bag of peanuts).
Because the famous onsen are heated, the best time to see the monkey troupe gathering in them is winter, specifically January and February. These months have the best chance of snow, which completed the postcard image associated with these celebrity primates. If you get a little jealous of the monkeys in their cozy baths, then you can head off to a number of nice onsen in the area yourself.
To get to the park, you can either take a bus to the parking lot and take a short walk, or trek around half an hour through the forest. Buses run to the park from several of the major onsen resorts and stations in the area.