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.

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.

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.

Afyonkarahisar

Resort hotel in Afyonkarahisar built around thermal pools, spa treatments and physical therapy, open to hotel guests.

Spa, Liège

Hotel spa in the town of Spa, Belgium, with a thermal pool, relaxation lounge and restaurant, open to day-pass visitors, not just hotel guests.

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.

Fort Lauderdale, Florida

Mokara Spa inside the Omni Fort Lauderdale Hotel has the area's only hammam, plus treatment rooms, a pool deck and rooftop bar, open to hotel guests only.

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.

The Hamptons, New York

A 29-room boutique hotel in Southampton with a poolside bathing club, relaxation lounge and restaurant, open to hotel guests only.

Ein Bokek, Southern District

A large hotel resort spa in Ein Bokek with two spa facilities, a thermal pool and 606 rooms overlooking the Dead Sea, 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.

Fort Lauderdale, Florida

A hotel spa at the Fort Lauderdale Marriott Harbor Beach Resort, open to hotel guests, with ocean views, a relaxation lounge and an on-site restaurant.

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.

Napa Valley, California

Spa Terra is the cave-set spa at Meritage Resort in Napa Valley, open to hotel guests with pools, a relaxation lounge and on-site dining nearby.

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

Santa Barbara, California

A hotel spa inside Hotel Californian in Lower State, Santa Barbara, with a thermal pool and relaxation lounge, open to hotel guests only.

Naples, Florida

A resort spa at the Hyatt Regency Coconut Point in Bonita Springs, open to hotel guests by reservation, with pool access on site.

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.

New Orleans, Louisiana

A hotel spa at the InterContinental New Orleans in the Central Business District, open to hotel guests only, with a relaxation lounge aimed at couples.

Cancún, Quintana Roo

A hotel spa at InterContinental Presidente Cancun Resort in Punta Cancun, open to hotel guests only, with an upscale price tier.

Scottsdale, Arizona

A resort spa at JW Marriott Phoenix Desert Ridge with a thermal pool, relaxation lounge and on-site café, open to hotel guests and day-pass visitors.