Spas with solo travelers

New York City, New York

A Flatiron bathhouse with six thermal pools, a banya, dry and infrared saunas, a steam room and a salt pool, day pass from $39.

Nashville, Tennessee

A Finnish-inspired bathhouse and salon in a converted East Nashville factory, with sauna, steam room, cold plunge and private suites for couples.

Denver, Colorado

Bathhouse in Denver's Ballpark District built around contrast therapy: a 40-person cedar sauna, eucalyptus steam room, five cold plunges, and thermal soaking

Gold Coast, Queensland

A 90-minute hydrotherapy circuit in Southport with a Finnish rock sauna, 5° ice baths and hot/cold magnesium pools, day pass $49.