Spas with solo travelers

Budapest

A centuries-old Turkish-style thermal bath on the Buda riverside with pools, saunas, massages and weekend late-night soaking hours.

Seattle, Washington

A clothing-optional outdoor hot pool, sauna and sun deck in Seattle's West Woodland, open to walk-ins for three-hour day visits.

Ibusuki, Kagoshima

Oceanfront outdoor onsen in Ibusuki where the two gender-assigned baths swap daily, with views of Mount Kaimon, the East China Sea, and Take-yama.

Aix-les-Bains, Auvergne-Rhône-Alpes

Medical thermal baths in Aix-les-Bains treating respiratory and oral mucosal conditions with sulfur-rich water, mostly through prescribed multi-day cures.

Noboribetsu, Hokkaido

A plain neighborhood bathhouse in Noboribetsu, Hokkaido, offering 100% source-fed hot spring water in two mineral varieties, about 10 minutes from the station.

New York City, New York

Thermal bath circuit and massages in a restored 1883 Tribeca textile factory, with a skylit tepidarium and candlelit thermal pools; reservation required.

Leukerbad, Valais

Thermal baths inside a 19th-century hotel in Leukerbad, Valais, with mineral-rich pools open daily from 9am to 8pm.

Ginzan Onsen, Yamagata

A no-frills communal bathhouse in Ginzan Onsen's Taisho-era hot spring street, open daily 8:30am-3:30pm except Wednesdays.

New York City, New York

A small Japanese-style bathhouse near Union Square with sauna, hot-tub onsen, cold plunge and a recovery lounge, open by reservation only.

Krabi

A moderately priced onsen-style day spa in Ao Nang, Krabi, open daily from late morning into the night.