Manza Kogen Hotel Sekitei Open-air Baths

Four colours of spring, eight open-air pools — mixed bathing in wraps for couples and families

Manza Onsen sits at 1,800 m, the highest hot-spring resort in Japan reachable by car year-round, and is known for strongly acidic milky water with the country’s highest sulphur content. Manza Kogen Hotel, a Prince Hotels resort, prides itself on variety of water rather than the views of its sister Manza Prince Hotel. Eight pools are scattered along the stream in the “Sekitei rotenburo”, each fed fully free-flowing from one of four private sources, so you can compare milky Uba-yu, yellow-green Ryusen-no-yu, the yellow Onigayu found only here in Manza, and clear Tsumatori-no-yu one by one. Seven of the eight are mixed bathing in wraps — rare in Japan — so couples and families can bathe together; women’s wraps are sold at the shop and a wrapped bath towel is acceptable. Snow-view bathing lasts until mid-April. Day use 11:00–18:00, ¥1,700.

Tips & cautions

- Wraps or bath towels are compulsory for both sexes in the mixed area. No cameras or phones.

- Strongly acidic (pH 1.5–2.5): stings cuts and eyes badly, blackens silver. Some don’t rinse afterwards, but sensitive skin should shower off.

- High altitude (1,800 m): no bathing after alcohol; short dips, repeated.

- Roads around Manza close at night for volcanic gas — check the Manza Highway (toll) route.

- Closures for groups and private hire — phone ahead (0279-97-1111).

- Free shuttle to Manza Prince Hotel; the ¥700 yu-meguri pass pays off from two baths.

Getting there

Seibu Kanko bus ~40 min from Manza-Kazawaguchi Station (JR Agatsuma line) to “Manza Kogen Hotel” (Manza Onsen, Tsumagoi-mura). From Tokyo: Shinkansen to Karuizawa, then Manza Highway bus ~1 h 45 min. By car ~1 h 40 min from Usui-Karuizawa IC via Route 146 and the Manza Highway (toll). Free parking.