Tsurunoyu Onsen

Japan's most photographed milky mixed bath, a thatched samurai-guard house with irori hearths, and rooms from about ¥11,700 — rustic, cold in places, and hard to book

Tsurunoyu is the oldest of Nyuto Onsen's eight inns: an Akita lord came to bathe here in 1638, and it has taken ordinary guests since the late 1600s. Its thatched honjin, once quarters for the lord's guards, and the milky-blue mixed outdoor bath are among the most famous images of rural Japan — and staying the night is the way to enjoy them, because from 10:00 day visitors 'pour in'. Four springs rise within 50 metres, feeding the mixed bath, a women-only outdoor bath, several indoor baths and two private baths; bloggers call the water superb, though several found the baths lukewarm. Dinner is yamanoimo-nabe (a mountain-yam dumpling hotpot), grilled iwana and mountain vegetables, served on lacquer trays or around an irori. This is an inn to go into with eyes open: the mixed bath has no women-only hours and towels aren't allowed; changing rooms and some washrooms are cold; rooms in the cheaper wings have no toilet, no air conditioning and fusuma walls that let through the noise of 24-hour bathers; honjin rooms can't be locked from outside; there's no TV or fridge; and stink bugs appear in autumn. Rooms fill months ahead — bookings open six months out by phone or through the Japan Hitou Association site.