The monkeys began using the hot spring in 1963 after observing humans using a nearby ryokan bath.
The macaques' thick fur allows them to withstand temperatures as low as -15 degrees Celsius.
Social grooming among the monkeys is a primary activity used to reinforce hierarchy and reduce stress.
The park was established specifically to provide a protected space for monkeys that were previously encroaching on local farmland.
The macaques exhibit clear social structures, including dominant alpha males and complex matrilineal lines.
Jigokudani Monkey Park is a research facility and viewing area where wild Japanese Macaques, or snow monkeys, bathe in a natural hot spring. The park is located within the Joshin'etsukogen National Park, situated in the valley of the Yokoyu River. It is the only place in the world where wild monkeys are known to naturally bathe in a man-made hot spring pool. The troop consists of approximately 160 individuals who live in the surrounding forest and descend to the park daily. The facility provides an observation area without fences or cages, allowing for close-up viewing of the animals in their habitat. The monkeys are not trained or fed by staff, ensuring their behaviors remain entirely wild. The park entrance requires a 1.6-kilometer hike through a forested trail from the nearest parking area.
The main observation deck overlooking the central hot spring pool provides the clearest view of the bathing monkeys.
Wear sturdy, non-slip waterproof hiking boots, as the trail can be muddy or icy depending on the season.
Do not make eye contact with the monkeys, as they interpret this as a sign of aggression.
Keep all food and drink completely out of sight and do not attempt to feed the animals.
Avoid visiting during the spring or autumn months if your primary goal is seeing the monkeys in the water, as they are less likely to bathe when the weather is mild.
Open year-round, though the trail may be closed during severe weather events or heavy snowfall for safety.
Do not touch, feed, or approach the monkeys; maintain a respectful distance at all times.
