Spas with hotel guests only

Miami, Florida

Hotel spa at The Ritz-Carlton Key Biscayne, Miami, with treatment suites, sauna, steam room and whirlpool, open to hotel guests 18 and up by appointment.

Chicago, Illinois

A hotel spa on Trump Chicago's mezzanine level offering day passes, 22 treatments, a heated pool, steam room, sauna and fitness club; minimum age 16.

Las Vegas, Nevada

A two-floor hotel spa inside Vdara with steam room, sauna, whirlpool and lounge, open only to Vdara and ARIA guests 18 and older, closed Tuesdays.

Pagosa Springs, Colorado

Hot springs resort in Pagosa Springs, Colorado, built around the geothermal Mother Spring, open daily for day-pass soaking or overnight stays.

Miami, Florida

Adults-only hotel spa on Belle Isle near South Beach with a hammam, sauna, ice room, infinity pool and a day pass option for non-guests.

Atlanta, Georgia

Hotel spa in Buckhead with 13 treatments, a heated lap pool, steam room and day passes for non-guests, set inside The Whitley.

Palm Springs, California

A 16-room adults-only hotel in Desert Hot Springs with three natural mineral-water pools fed by a 350-foot geothermal well, plus a small on-site spa and

Orlando, Florida

Adults-only hotel spa at the Hilton Orlando with a sauna, steam room, cold plunge and thermal pools, plus couples treatments and HydraFacials.

Bridgetown, Christ Church

Hotel spa at Accra Beach Hotel in Christ Church, Barbados, with six treatment rooms, a sauna and steam room, open daily 8am-7pm for hotel guests.

Boston, Massachusetts

Hotel spa inside the Omni Boston Hotel at the Seaport, with eight treatment rooms and a rooftop pool, open to hotel guests only.

Osprey, Florida

Hotel spa and pool deck at a moderate-price resort in Osprey, Florida, with sauna, steam room and thermal circuits for overnight guests.

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.

Scottsdale, Arizona

Hotel spa at the mid-century Hotel Valley Ho in South Scottsdale, with sauna, steam room and two pools, open to hotel guests only.

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.

Miami, Florida

Hotel spa at The Ritz-Carlton, South Beach on Lincoln Road, with massages, facials and an outdoor pool with whirlpool, for hotel guests.

Scottsdale, Arizona

A hotel spa at Four Seasons Scottsdale at Troon North offering massages, facials, a full salon and 24-hour fitness access, guests only.

Carmel-by-the-Sea, California

A hotel spa at Quail Lodge and Golf Club in Carmel-by-the-Sea with a steam room, three private fitness cabanas and a heated outdoor pool, limited to hotel

Holmes Beach, Florida

A beachfront resort on Anna Maria Island with a spa, sauna, steam room and pool, open to hotel guests, mainly geared toward couples.

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.

Fort Lauderdale, Florida

Hotel spa at The Atlantic Resort on Fort Lauderdale Beach with sauna, steam room, cold plunge and thermal pool, for overnight guests only.

Scottsdale, Arizona

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

San Diego, California

A rooftop hotel spa in San Diego's Gaslamp Quarter offering treatments and a 24/7 fitness center, open to hotel guests and day-pass visitors.

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