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.

Portland, Oregon

Neighborhood day spa in Portland's Overlook area with a private soak-and-steam retreat studio, massage, skincare and nail services.

Napa Valley, California

A boutique day spa in downtown Napa Valley with nine treatment rooms offering massage, facials and body work, plus sauna, steam and a thermal pool.

Miami, Florida

A beachfront resort spa in North Beach, Miami with cryotherapy, a floating salt bath, sauna, steam and a cold plunge, open to walk-ins and day-pass guests.

Bursa

A historic thermal bathhouse and small hotel in Bursa's Kükürtlü district, with separate men's and women's hamams, day passes, and overnight stays.

San Diego, California

A walk-in day spa in San Diego's Hillcrest neighborhood with massage, cryotherapy, salt therapy and a $100 all-day wellness pass.

Tucson, Arizona

Hotel spa at Omni Tucson National Resort with 12 treatment rooms, a couples suite, salon services, and day passes open to both guests and locals.

Budapest

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

Karlovy Vary, Karlovy Vary Region

A one-room beer bath spa in a 18th-century cellar in central Karlovy Vary, with unlimited beer, oak tubs and a straw-bed rest area.

Dax, Nouvelle-Aquitaine

A walk-in day spa in Dax with pool, sauna, hammam and Norwegian bath access, plus facials, massages and aquabike classes.

Aix-les-Bains, Auvergne-Rhône-Alpes

An upscale day spa inside Hotel Le Riviera in Aix-les-Bains, with pools, saunas, a hammam and eight treatment rooms open to walk-ins.

Miami, Florida

AVEDA hotel spa at The Palms in Mid-Beach Miami, offering Ayurvedic-inspired massages, facials and salon services with pool and beach access included.

Las Vegas, Nevada

Hotel spa on the Palms casino level in Las Vegas with steam rooms, saunas, a seasonal pool and 32 treatments including massage, facials and body work.

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Los Angeles, California

A 24-hour Korean jjimjilbang on Wilshire Blvd in Westlake with single-sex bathing floors, a family-friendly sauna level and a rooftop terrace.

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.

Palm Beach, Florida

A Juno Beach day spa with sauna, steam room and pool, offering massages, facials and couples treatments since 2008.

Coorg, Karnataka

A luxury coffee-plantation resort in Coorg with a spa and pool facilities reserved for overnight guests.