Shin-Appi Onsen Seiryukaku

Seiryukaku is a one-inn hot spring in Kamasuda, Hachimantai City, Iwate Prefecture, about three minutes by car from Ashiro IC on the Tohoku Expressway. The inn has two guest buildings, Rindokan and Ajisaikan, and also accepts day-trip bathers.

The water is a fossil-seawater type strong saline spring, classified as sodium chloride strong salt spring. It holds roughly 33 grams of dissolved solids per liter, more than three times the threshold for a hypertonic spring. The source emerges at 32.4 C with a neutral pH of 6.9 and is used at about 42 C. The cloudy, pale yellowish-brown water also contains metaboric acid and sodium bicarbonate. The main source bath, Kin no Yu, is kakenagashi (continuous free-flowing), with about 10 percent hot water added to adjust the temperature.

The baths are Kin no Yu, a large bath with a sauna and an open-air section, Gin no Yu, a large bath without a sauna, and Mori no Rotenburo, an open-air bath with three kinds of tubs. All are separated by gender, and a private bath can be reserved by the day before. Day-trip admission is 1,000 yen for adults (junior high school and older), 700 yen for elementary school children and 600 yen for younger children, paid at the Rindokan front desk.