Jigokudani Snow Monkey Park (Wild Japanese Macaques Bathing in Alpine Hot Springs)

Category: Alpine Wildlife Sanctuary & Geothermal Hot Springs | Location: 6845 Hirao, Yamanouchi-machi, Shimotakai-gun, Nagano 381-0401 (Nagaden Bus from Yudanaka Station)

Nestled in the steep, shadowed gorge of the Yokoyu River in northern Nagano Prefecture, the Jigokudani Yaen-Koen (Jigokudani Snow Monkey Park) was founded in 1964 as a cage-free natural habitat sanctuary. Surrounded by forbidding volcanic cliffs draped in deep snow for nearly four months of the year, the chasm was historically branded "Hell’s Valley" (*Jigokudani*) due to plumes of boiling geothermal steam hissing from rocky crevices. The park attained global celebrity status when National Geographic and international documentary crews documented its troop of wild Japanese macaques (*Macaca fuscata*) regularly relaxing inside thermal hot spring pools. This extraordinary primate behavior originated organically during the frigid winter of the early 1960s when a curious juvenile macaque imitated human bathers at the nearby rustic Korakukan ryokan and leaped into an outdoor thermal pool to escape subzero winds. Over generations, this ingenious learned behavior was transmitted culturally from mother to offspring, prompting the sanctuary to construct a dedicated geothermal bath exclusively for the troop. Today, travelers witness wild macaques with frost-dusted golden fur soaking peacefully up to their chins, grooming kin, or dozing off with expressions of blissful euphoria amid billowing steam as surrounding air temperatures plummet past minus 10°C. Reaching the geothermal sanctuary involves an invigorating 1.6-kilometer (30-minute) trek through a serene, ancient forest of Japanese cedar (*Sugi*) and larch from the trailhead at Kanbayashi Onsen. Operating without cages, fences, or artificial enclosures, the macaques roam completely free between the mountain crags and the riverbed, allowing respectful visitors to witness untouched wild primate sociology and family bonds at arm’s length.