Jigokudani Yaen Koen and the hot-spring snow monkeys
Published on 09/16/2026 at 10:47 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS
Jigokudani Yaen Koen in Yamanouchi, Nagano Prefecture, is a mountain valley park where wild Japanese macaques gather around a steaming hot spring pool in winter snow. The park stands in the Jigokudani valley of the Yokoyu River inside Joshinetsu Kogen National Park, with cliffs, forested slopes and rising steam giving the setting its “Hell’s Valley” name.Jigokudani Monkey Park
Snow monkeys in a volcanic valley
The centrepiece of Jigokudani Yaen Koen is a concrete-edged hot spring pool built beside natural thermal vents in the valley, where the resident troop of Japanese macaques has been observed soaking since the 1960s.The Snow Monkey Park was established in 1964 The surrounding slopes are punctuated by bare rock and fumaroles, with clouds of sulphurous steam rising between winter snows and evergreen trees.
The park sits roughly 850 m (2,789 ft) above sea level in the mountains of Yamanouchi Town, an altitude that leaves the valley under snow for many weeks of the year.Jigokudani Yaen-koen is located 850 meters above sea level Snow piles on the steps, trees and boulders around the bathing pool, so the brown fur and red faces of the macaques stand out against white drifts and grey rock.
From research ground to year-round observation park
Jigokudani Yaen Koen took shape in the mid-1960s, when a designated observation area was created to study the social behaviour of Japanese macaques living in the valley’s harsh climate.The Jigokudani Wild Snow Monkey Park was established in 1964 The park has remained a place where the monkeys move freely between forest and pool, with no cages or fences separating them from the landscape.
Later accounts describe how hundreds of macaques inhabit the wider Jigokudani area, with a core group descending to the pool and feeding terraces where they can be watched at close range.Over 160 Japanese Macaque monkeys inhabit the area The onsen towns of Shibu and Yudanaka lie downstream along the Yokoyu River, making the valley part of a broader hot spring region where geothermal water shapes both human bathing culture and this unusual animal spectacle.
Layout, trail and surrounding landscape
Reaching Jigokudani Yaen Koen means following a forest trail along the valley side, climbing gently above the Yokoyu River until the smell of volcanic gases and the sight of rising steam signal the approach to the park.The park is located in the forests of the Jigokudani valley The final section passes simple service buildings and rock walls before opening onto the viewing area around the pool.
The park buildings are modest structures of timber and concrete, with railings, steps and platforms set against the cliff to give clear views of the pool and the terraces where macaques groom, climb and search the ground. Beyond the enclosure, the valley narrows into a ravine, the river cutting through boulders with hot spring outflows staining the rocks and riverbanks.
Visiting Jigokudani Yaen Koen: what travellers from Western Europe should know
- Jigokudani Yaen Koen lies behind Yamanouchi in Nagano Prefecture, in the Jigokudani valley of the Yokoyu River, near the hot spring towns of Shibu and Yudanaka.
- The approach to the park includes a forest trail with a noticeable gradient, unpaved sections and flights of steps, which can be snow-covered and muddy in cold seasons.
- The official language is Japanese and the currency is the Japanese yen.
- Entry requirements depend on your nationality; UK travellers can check the FCDO travel advice at gov.uk/foreign-travel-advice, Irish travellers the Department of Foreign Affairs at ireland.ie.
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Frequently asked questions about Jigokudani Yaen Koen
Where is Jigokudani Yaen Koen located?
Jigokudani Yaen Koen is in Yamanouchi Town in Nagano Prefecture, in the Jigokudani valley of the Yokoyu River inside Joshinetsu Kogen National Park.
What should visitors expect on a visit?
Visitors follow a forest trail to a compact park built around a hot spring pool, where wild Japanese macaques move freely across terraces, rocks and nearby slopes.
What makes Jigokudani Yaen Koen distinctive?
The park is distinctive for its combination of a volcanic ravine, heavy winter snow and macaques that bathe in geothermal water in an unfenced mountain setting.
