The oldest inn in the Nyuto Onsen area, a hidden hot spring dating to the Edo period. The thatched 'Honjin' building and the large milky-white mixed rotenburo are its iconic scene. Day bathing 10:00–15:00; on Mondays the rotenburo is closed for cleaning and only indoor baths are open. Rooms sell out months ahead. From Tazawako Station take the bus, then the inn shuttle from Alpa Komakusa.
The innermost of Nyūtō's seven baths — a cluster of thatched bath huts. Two separate sources feed a mixed open-air pool and gender-separated indoor/outdoor baths of milky sulfur water. Day use 9 am–4 pm, the longest window of the seven; closed mid-November to mid-April.
The most polished of the seven Nyūtō inns, beside the Sendatsu stream and popular with women. Two sources — rusty 'gold' and clear 'silver' — in open-air baths above the rushing river. Day-use reception is short (10:30 am–2 pm), so come early.
A single inn at the end of the Nyūtō bus line, wrapped in old-growth beech forest and named for the river crabs once abundant in the nearby stream. Unusually for Nyūtō, the water is clear and colourless — a bicarbonate spring with drifting white flakes and a gentle feel. The signature is Karako-no-yu, a mixed open-air pool some 50 m from the building in the woods, magical in snow season; there are also separate indoor wooden and rock baths. Day use 9:00–16:30, ¥800. Covered by the Yumeguri-chō pass (¥2,500, valid one year) for all seven Nyūtō inns — the classic combo is with Tsuru-no-yu and Taenoyu. About 50 minutes by bus from Tazawako Station to the Nyūtō Onsen stop.