Spas with solo travelers

Vail, Colorado

Walk-in recovery clinic in Lionshead, Vail offering IV therapy, compression boots, cryo, red light and hyperbaric treatments aimed at skiers and athletes.

Boston, Massachusetts

A Seaport social wellness club in Boston offering saunas, ice baths, IV therapy, red light and HBOT sessions, with reservations required and no membership

Houston, Texas

A Houston day spa near Memorial Park offering massage, facials and spa packages, with a sauna, steam room and pool on site.

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.

Santa Fe, New Mexico

A small Santa Fe day spa centered on a halotherapy salt room, with sauna and ionic foot detox add-ons, booked by reservation only.

Denver, Colorado

A Denver day spa in Speer built around the Vietnamese Red Dao herbal bath, with infrared sauna, salt chamber and foot baths, open daily 10am-6pm.

Scottsdale, Arizona

Hotel spa at the Inn at Eagle Mountain in Fountain Hills with sauna, steam room, pools and a $69 60-minute massage as its signature treatment.

Sedona, Arizona

A moderately priced day spa in Sedona with outdoor gardens, a hot tub and fountains, known for its Prickly Pear Pomegranate body treatment.

Asheville, North Carolina

A day spa inside Asheville's Hilton at Biltmore Park offering massage, organic skincare and nail care, with day-pass access to a pool, hot tub and gym.

Asheville, North Carolina

A Japanese-inspired destination spa on a mountainside outside downtown Asheville, built around private outdoor salt hydrotherapy tubs and massage.

Auckland

Hotel day spa at Pullman Auckland CBD with a 25m heated pool, sauna, steam room, jacuzzi and gym plus massage and facial treatments.

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.

Naples, Florida

Upscale day spa in Naples offering infrared sauna, massage, facials and foot detox, with a $230 signature massage and couples packages.

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.

Vail, Colorado

A day spa and recovery club in downtown Vail with hot tub, sauna, steam room, cold plunge and salt lounge, plus day passes and fitness access.

Santa Fe, New Mexico

Small hotel spa at Hotel Loretto in downtown Santa Fe offering two seasonal treatments by reservation, no walk-in day pass.