Hito Nagano-yu (Nagayu Onsen)

Nagano-yu is a rustic day-use bathhouse in the Nagayu Onsen area of Naoiri, Taketa, Oita Prefecture, set among rice paddies a little apart from the main hot spring row along the Serigawa River. Nagayu Onsen is renowned as one of the world's finest carbonated springs, blessed with an exceptional combination of dissolved CO2, discharge volume and temperature. Nagano-yu is a small, unmanned bathhouse in this district, with an adjoining campground and a quiet, secluded setting.

The water is a calcium-magnesium-sodium bicarbonate-sulfate spring; the addition of a sulfate component to the bicarbonate spring is unusual even within the Nagayu district. The source emerges at about 45C and is served as genuine free-flowing kakenagashi with no added water, no reheating, no circulation and no chlorination. As you soak, fine bubbles cling gently to the skin, boosting circulation and warming the body from its core. The water is said to help with fatigue, neuralgia, muscle pain, poor circulation, high blood pressure and chronic digestive complaints.

The facility has separate large baths for men and women (one each) plus four private rental baths popular with families and couples, all available at very low prices. The public baths cost 200 yen for adults and 100 yen for children of elementary age and under, while a private bath is 1,000 yen for 50 minutes. It is open from 6:00 to midnight, closing for maintenance on Mondays, Wednesdays and Fridays from 9:00 to noon. Free parking is available for about 16 cars.