Spas with solo travelers

Charleston, South Carolina

Contrast therapy studio in Mt Pleasant offering private 60-minute sessions with infrared sauna, cold plunge and vitamin-c shower; day pass $60.

Palm Beach, Florida

A Palm Beach Gardens studio offering 60-minute private-suite sessions combining infrared sauna, cold plunge and vitamin-c shower.

Charleston, South Carolina

Private contrast-therapy suites with infrared sauna, cold plunge and vitamin C shower in West Ashley, Charleston, by reservation.

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.

Taos, New Mexico

Hotel day spa at El Monte Sagrado in Taos with a hydrotherapy circuit, saltwater pool and treatment rooms, open daily, day passes available.

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.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

Los Angeles, California

Four Seasons hotel spa in Beverly Hills with a steam room, rooftop pool, fitness center and eight treatments, open daily, day passes available.

Houston, Texas

A Four Seasons hotel spa in downtown Houston with three treatment rooms, a couples' suite and rooftop pool access, open to day-pass guests.

Milan, Lombardy

A luxury hotel spa inside Four Seasons Hotel Milano with a 14-metre pool under a vaulted ceiling, sauna, gym and private suites for couples' treatments.

Chicago, Illinois

A 5th-floor day spa inside the Palmer House Hilton in the Loop, built around a hydrotherapy circuit, Vichy shower treatments and a facial called Glow Revival.

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.

San Diego, California

Resort spa on Mission Bay offering massages, facials and body treatments, with walk-ins welcome and a gym and yoga classes on-site.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

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.

San Pedro de Atacama, Antofagasta

A hotel spa inside the luxury Tierra Atacama lodge near San Pedro de Atacama, with indoor and infinity pools, sauna, steam room and treatment rooms, open only

Rogaška Slatina, Savinjska

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

Miami, Florida

Hotel spa at The Setai in Miami Beach with 7 ocean-view treatment rooms, 5 couples suites, saunas, steam and a cold plunge.

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.

Los Angeles, California

Day spa in West Hollywood with wet and dry banyas, pool, sauna, cold plunge and café; day pass is $110, walk-ins welcome.

Auckland

A family-run rainforest resort in the Waitakere Ranges near Auckland offering a day spa, private yoga and free hiking and biking trails.

Orlando, Florida

A hotel spa at Waldorf Astoria Orlando offering massages, facials and a Himalayan salt room, open daily 9am-5pm with day passes available.

Galle, Southern Province

Oceanfront hotel spa at Radisson Collection Resort Galle, open daily 9am-9pm with walk-ins, sauna, steam, pools and Ayurvedic treatments from $65.

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.