Spas with upscale

San Diego, California

Hotel spa at Carté Hotel San Diego Downtown with a heated saltwater pool, whirlpool, 28,000 sq ft fitness club with sauna and steam room, open to guests only.

Oaxaca

An all-inclusive beachfront resort spa in Huatulco with a sauna, steam room and thermal pools, open only to hotel guests.

Cancún, Quintana Roo

The spa at this all-inclusive Puerto Morelos resort offers hydrotherapy, massages and facials for hotel guests only.

Miami, Florida

A hotel spa at Eden Roc Miami Beach in Mid-Beach with sauna, steam room, cold plunge and thermal circuits, open to resort guests only.

Taos, New Mexico

A boutique skin and body studio in Taos offering facials, lymphatic massage, Endermologie and head spa treatments by appointment.

Kamijima, Ehime

An all-inclusive resort on Yugejima island in Setouchi's inland sea, with ocean-view outdoor baths, ocean-front rooms, and a day-pass option.

Punta Cana, La Altagracia

A hotel spa inside the adults-only JOIA Bávaro by Iberostar beach resort in Punta Cana, open only to overnight guests.

San Diego, California

Hotel spa on Shelter Island in San Diego with sauna, steam room, and pool, open to guests staying at Kona Kai Resort.

Catskills, New York

A Catskills retreat center with a Tibetan-style spa offering sauna, steam, pools and cold plunge, built around overnight stays and group programs.

Kyle, Texas

A 88-acre Hill Country resort near Kyle and Wimberley with overnight rooms, a garden spa, pool, hot tubs and day-pass access by reservation.

San Diego, California

A hotel spa on Mission Bay in San Diego with sauna, steam room, cold plunge and thermal pools, open only to resort guests.

Park City, Utah

Serenity Spa is the treatment center inside Westgate Park City Resort, a ski-in villa resort with a year-round indoor/outdoor pool, sauna and steam room for

Opelika, Alabama

A hotel spa inside the Auburn Marriott Opelika Resort on the Robert Trent Jones Trail golf course, open to hotel guests.

Adairsville, Georgia

A resort spa at Barnsley Resort in Adairsville, Georgia, offering massage, facials, reflexology, sauna and steam room, open to hotel guests only.

Scottsdale, Arizona

A hotel spa at the 65-acre Fairmont Scottsdale Princess resort in North Scottsdale, open to overnight guests with sauna, steam room and pool access.

Atami, Shizuoka

A hotel spa in Atami with a thermal onsen pool, open only to overnight guests staying at Fufu Atami.

Sint Eustatius

A 40-acre dive-and-stay resort on Sint Eustatius with a pool, restaurant and shuttle service to its dive center, open only to overnight guests.

Scarborough

A boutique hillside hotel above Bacolet Bay in Scarborough, Tobago, with an infinity pool and ocean views, built around a converted 150-year-old Donkey Cart

Catskills, New York

Adults-only resort spa in the Catskills with sauna, hot tub, yoga studio and overnight stays for hotel guests only.

Huntington Beach, California

An adults-only hydrotherapy circuit with hot tub, sauna and steam room for guests staying at this beachfront Hyatt Regency resort in Huntington Beach.

San Juan Capistrano, California

A hotel spa at the Autograph Collection's Inn at the Mission in San Juan Capistrano, open to overnight guests with a relaxation lounge on site.

Portsmouth, Saint John Parish

A hotel spa inside the InterContinental Dominica Cabrits Resort, open to overnight guests staying within Cabrits National Park near Portsmouth.

Austin, Texas

A lakeside resort spa on Lake Travis in Lakeway, Texas, with pools, outdoor baths and treatments, open only to hotel guests.

Palm Springs, California

A hotel spa at Palm Springs' Riviera Resort & Spa, open only to overnight guests and paired with a pool, restaurant and bar.