Spas with upscale

Oaxaca

A traditional four-door temazcal steam ceremony about 15-20 minutes outside Oaxaca city, paired with an ice-water plunge and overnight rooms.

Sonoma, California

Hotel spa at The Lodge at Sonoma with an outdoor terrace, soaking pool, plunge pool and barrel sauna, open daily 9am-5pm, adults-only, reservation required.

Berlin

A saltwater thermal pool under a concrete dome near Berlin's Tempelhofer Feld, with sauna, steam room and occasional DJ nights.

Ojo Caliente, New Mexico

Historic New Mexico hot springs resort with communal mineral pools, private tubs, and day-pass soaking near Taos.

Park City, Utah

A ten-treatment-room spa inside the private Promontory Club in Park City, with a full hydrotherapy circuit of steam, sauna and cold plunge.

Sedona, Arizona

A resort spa at Amara in Sedona with outdoor baths, an infinity pool and a relaxation lounge, open only to hotel guests.

Rishikesh, Uttarakhand

An upscale riverside resort 18 km outside Rishikesh with an in-house spa, yoga studio and restaurant, open only to overnight guests by reservation.

San Francisco, California

Hotel spa on the 8th floor of 1 Hotel San Francisco with rooftop stone soaking tubs and Bamford skincare treatments, open daily for day visitors.

Milwaukee, Wisconsin

East Town Spa in Milwaukee's Juneau Town combines a full-service salon and med spa with a thermal circuit of sauna, steam, pools and cold plunge.

Mérida, Yucatán

Resort spa on the grounds of Hacienda Xcanatun near Mérida, with a pavilion over a pond offering Asian-style massages and facials by reservation.

Puyehue, Los Lagos

A forest resort spa in Puyehue, Chile, with volcanic thermal pools and outdoor baths, open only to hotel guests.

Leukerbad, Valais

A 30-room hotel in Leukerbad with a private thermal pool and sauna chalet, open to overnight guests only, overlooking the Gemmi massif.

Dallas, Texas

A hotel spa at Omni Las Colinas in Irving, Texas, with an outdoor pool and bath area, open to hotel guests along Lake Carolyn.

Scottsdale, Arizona

Hotel-guests-only spa at Scottsdale's Kimpton Miralina, with sauna, cold plunge and desert-inspired massages, mud wraps and facials.

Key West, Florida

Hotel day spa at Casa Marina in Key West offering ocean-view massages, facials and beachside yoga, walk-ins welcome.

Barcelona, Catalonia

Rooftop day spa at Casa Bonay hotel in Eixample with dry sauna, hammam, ice bath and a Japanese ofuro, booked by small-group circuit or free use.

Asheville, North Carolina

Resort spa on an 85-acre Hendersonville farm near Asheville, with massage treatments in a converted horse barn, day passes, and a pool with sauna, steam and

Santa Fe, New Mexico

Hotel spa at La Fonda on the Plaza in downtown Santa Fe, with a heated outdoor pool, hot tub, fitness center and relaxation lounge for guests of the hotel.

Vichy, Auvergne-Rhône-Alpes

Adults-only thermal baths in Vichy using the town's mineral spring water, with a hydrotherapy circuit and thermal pool, booking required.

The Hamptons, New York

A membership-based wellness club in Southampton with a stadium-seating sauna, cold plunge pools, treatment suites and group classes.

Scottsdale, Arizona

Adults-only resort spa in Fountain Hills with sauna, steam room and outdoor pools, offering day passes and an amethyst facial as its signature treatment.

Santa Cruz, California

A hotel spa on a 300-acre Santa Cruz hilltop with Monterey Bay views, outdoor baths and a relaxation lounge, open only to resort guests.

Cancún, Quintana Roo

A boutique hotel near Cancún airport with a small wellness wing — pool, jacuzzi, sauna, steam room and temazcal — open to day-pass visitors.

San Antonio, Texas

Full-service resort spa at the Hyatt Regency Hill Country in San Antonio, with thermal circuits, cold plunge and day passes open to non-guests.