Spas with upscale

Tucson, Arizona

Six-room hotel spa at Hacienda del Sol in Tucson, open daily 9-6, taking both resort guests and local walk-ins for massages, facials and body treatments.

San Diego, California

Adults-only day and hotel spa in Rancho Bernardo with gardens, whirlpools, a steam room and an 18-treatment menu, open daily 9am-6pm.

Calistoga, California

A 20,000-square-foot resort spa in Calistoga with five geothermal pools, Calistoga mud treatments, and a day pass for non-hotel guests.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Naples, Florida

A boutique hotel in downtown Naples with a heated outdoor pool, whirlpool spa and cabanas, open only to overnight guests.

San Diego, California

A La Jolla medical spa specializing in lymphatic drainage, colon hydrotherapy and detox treatments, open since 1993, adults only, by reservation.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Hilton Head Island, South Carolina

Hotel spa inside an oceanfront Hilton Head resort, offering massages, facials, body treatments and manicures to overnight guests.

Palm Springs, California

Boutique hotel spa in Desert Hot Springs with two natural mineral hot spring pools, day passes, and overnight rooms that include breakfast.

Palm Springs, California

Downtown Palm Springs day spa built around a natural hot mineral spring, with private mineral baths, sauna, steam room and massage.

Tucson, Arizona

A hotel spa inside the 1929 Hacienda del Sol Guest Ranch Resort in Tucson, offering facials, massages and body treatments to resort guests only.

Tucson, Arizona

Lakeside Spa at this 398-room desert resort in Tucson is open to hotel guests only, with two heated pools, a Jacuzzi and mountain views of Catalina range.

San Diego, California

A resort spa on a 44-acre Mission Bay island in San Diego, open to hotel guests, with sauna, steam room and pool access.

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.

San Francisco, California

Adults-only hotel spa in Sausalito, California, offering day passes alongside yoga and a restaurant on site.

Encinitas, California

Adults-only day spa in Leucadia, Encinitas, about a mile from the beach, with private suites, a relaxation lounge and movement classes.

Riviera Maya, Quintana Roo

Beachfront all-inclusive resort in Playa del Carmen with a hydrothermal circuit spa available to hotel guests for an extra charge.

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.

Riviera Maya, Quintana Roo

A resort spa inside the Iberostar Waves Tucán in Playacar offering sauna, Turkish bath and jet-pool treatments, open to day-pass visitors 16 and up.

Jekyll Island, Georgia

Hotel spa at Jekyll Island Club Resort offers outdoor baths and a pool with ocean views, open only to resort guests.

Tulum, Quintana Roo

A boutique hotel resort in Tulum's Aldea Zama with two pools, a yoga terrace and a rooftop restaurant, open to overnight guests rather than day visitors.

San Juan

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.

Riviera Maya, Quintana Roo

Beachfront resort spa in Playa del Carmen built around Mayan wellness themes, open to hotel guests only, with yoga sessions and a relaxation lounge.