Pleasant in winter when shrouded in snow but less appealing when seasonally bare, Jigokudani Monkey Park is wildly popular. Made famous by the 1992 film Baraka, where wild monkeys appear to bathe in natural onsen pools, the park sees thousands flock here each year to view the over-photographed troupe of wild Japanese macaques who are lured into the park with food. Many visitors are looking for that classic photo of a monkey in the steaming rotemburo with snow on its head.
While it's all good fun getting in there among the monkeys, a few points need to be noted beforehand. The monkeys are wild and not always there – confirm their presence before you start the 1.6km walk through the forest from the car park to the Monkey Park by asking the car-park attendant. There's also a webcam link on the Monkey Park website where you can see what's going on.
The monkeys generally only go into the human-made onsen when the weather is cold. Keep in mind that these are wild monkeys and treat them as such: don't go in too close for that friendly photo.
In winter, when snow hides the industrial debris, it's all quite appealing, but when there's no snow around, don't expect an overly attractive environment by the river.
A rental car will make life a lot easier here, but getting to the Monkey Park by public transport is also possible. Take the Nagano Dentetsu line from Nagano to the Yudanaka terminus (tokkyū ¥1260, 45 minutes), then take the bus for Kanbayashi Onsen Guchi and get off at Kanbayashi Onsen (¥230, 15 minutes, eight daily). Walk uphill along the road for about 400m until you see the sign reading 'Monkey Park', then begin your 1.6km walk through the forest.