Yudanaka Onsen 湯田中温泉 — Nagano
Reservable private bath
Two big reservable semi-open-air baths — one rock, one hinoki — and both are free. The water is 100% source water drawn from three springs and kept constantly flowing.
The private bath works like this: you book it, it's yours. Door closed, steam up, nobody else's schedule anywhere near you. Take the late slot — night air on wet skin is the whole point.
Private-bath and water facts were checked against the property's official site and Japanese booking pages in November 2026. Room plans change — confirm the private bath is included in the plan you book.
More in Yudanaka Onsen
Every guest room's unit bath runs on natural hot spring water here — a Taisho-era source found bubbling up through the riverbed sand — and the shared scenic open-air bath looks over the town.
A small family inn where the hinoki bath is yours alone: write your room number on the board when it's free and lock the door behind you. The water is the inn's own 100% natural spring.
Until 7pm the inn's bath runs on reservations only — pick a 55-minute slot at check-in and the hinoki bath is entirely yours, filled with natural spring water poured straight from the source: no heating, no added water.