Spas with hotel guests only

Calistoga, California

A 25-room Sonoma hotel in Forestville with a spa barn offering sauna, steam and pools, mainly for 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.

Afyonkarahisar

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

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.

Rancho Santa Fe, California

A Spanish Colonial-style luxury resort spa in Rancho Santa Fe near San Diego, open only to overnight guests, with 49 casitas and 45 acres of grounds.

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.

Warwick, Rhode Island

A boutique Hilton hotel in a converted Warwick textile mill offering guests a sauna and fitness center, with no public day-spa access.

Chiang Mai, Northern Thailand

A hotel spa inside the Four Seasons Resort Chiang Mai in Mae Rim, with sauna, steam room, cold plunge and thermal pools set among rice paddies, open to resort

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.

Mykonos, South Aegean

A hotel spa inside Cavo Tagoo Mykonos, open only to guests staying at this luxury resort overlooking the Aegean.

Puerto Vallarta, Jalisco

A resort spa inside the all-inclusive Dreams Bahia Mita Surf & Spa Resort on Banderas Bay near Punta de Mita, open to hotel guests only.

Mazatlán, Sinaloa

Hotel spa at an all-inclusive beach resort in Mazatlán, offering a hydrotherapy circuit, Hammam and massage treatments for registered guests only.

Tulum, Quintana Roo

Resort spa at an all-inclusive Tulum beach hotel, with hydrotherapy, jungle and beach-side treatment cabins, 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.

Miami, Florida

Hotel spa at the Fontainebleau Miami Beach resort on Collins Ave, open to hotel guests only.

Denver, Colorado

Hotel spa inside the Four Seasons Denver, open to hotel guests only, with treatment rooms, sauna and a fitness center in the Central Business District.

Houston, Texas

A hotel spa inside the 30-storey Four Seasons in downtown Houston, with rooftop pool access, open only to hotel guests.

Miami, Florida

A hotel spa inside the Four Seasons in Brickell, reserved for hotel guests, with rooftop pool and bay views as part of the stay.

Nashville, Tennessee

Hotel spa inside the Four Seasons in downtown Nashville's SoBro district, open to hotel guests, with a rooftop pool over the Cumberland River.

Philadelphia, Pennsylvania

A hotel spa inside the Four Seasons Comcast Center tower in Center City Philadelphia, open to overnight guests with an infinity pool and skyline views.

Seattle, Washington

A hotel spa inside the Four Seasons Seattle, open only to hotel guests, with Elliott Bay views and an on-site fitness center.

Palm Beach, Florida

Oceanfront resort spa at the Four Seasons Palm Beach, open to hotel guests only, with thermal pool, relaxation lounge and ocean-view pool deck.

Scottsdale, Arizona

A hotel-guests-only resort spa at the foot of Pinnacle Peak in Scottsdale, with a bi-level pool, hot tub and Southwest-inspired treatments.