In Jigokudani Monkey Park, located in Yamanouchi, Shimotakai District, Nagano Prefecture, you can witness the natural habitat of Japanese macaques. This park is a popular tourist spot known for its monkeys soaking in hot springs during winter. It's highly favored by international visitors and is also referred to as the Snow Monkey Park.
The closest access point to the Jigokudani Monkey Park is the Jigokudani Parking Lot (500 yen per car). It's a 15-minute walk from the parking lot to the Jigokudani Monkey Park and provides the shortest route. The path is easy to walk, and even when accompanied by young children, we had no issues reaching the park.
However, the mountain road to the Jigokudani Parking Lot is narrow. It was a bit challenging as the road was too narrow for cars to pass each other comfortably.
During winter, the road to the Jigokudani Parking Lot is closed. Instead, visitors can park at the dedicated parking lot in Kanbayashi Onsen (free) and walk for about 30 minutes to reach the park. As it's a mountain trail, I recommend wearing comfortable shoes that can get dirty.
I visited the Jigokudani Monkey Park in August 2017. It was hot, so the monkeys weren't soaking in the hot springs, but I saw some incredibly cute monkeys.
Along the path leading to the entrance of Jigokudani Monkey Park, you'll come across the intermittent geyser called 'Shibu no Jigokudani Fountain.
The hot spring gushing from the riverbed forms a natural geyser that reaches a height of up to 20 meters, designated as a national natural monument. It's the source spring of the Jigokudani Onsen Ryokan 'Jigokudani Onsen Korakukan.' Currently, only this 'Shibu no Jigokudani Fountain' remains, but in the past, there were numerous geysers. The area was named 'Jigokudani,' meaning 'Hell Valley,' as the sounds of geysers roaring from the bottom of the hell echoed around, but now only this particular fountain exists.