Yudanaka Onsen

Yudanaka Onsen sits in the Shiga Kogen foothills of northern Nagano, a compact hot-spring town perched above the Yokoyu River and known internationally as the gateway to Jigokudani Monkey Park, where snow macaques warm themselves in open-air thermal pools each winter. That vivid natural spectacle has introduced many foreign visitors to Yudanaka, though the onsen town itself has been welcoming human bathers for centuries longer.

The waters are bicarbonate in character, emerging at 40 °C with an alkaline pH of 8.0 that produces a notably smooth, almost silky quality on the skin. Traditional wooden bathhouses line the narrow lanes of the old quarter, maintaining an aesthetic that resists the renovation impulse of more commercialised resorts — making Yudanaka among the more atmospheric surviving examples of the old-fashioned Nagano onsen village, valued by travellers who come for the baths as much as for the photogenic monkeys.