Spas with fitness center

Palm Springs, California

A 38,000-square-foot resort spa at JW Marriott Desert Springs in Palm Desert offers day passes, saunas, a saltwater lap pool and couples suites.

Boston, Massachusetts

Adults-only hotel spa at Encore Boston Harbor in Everett with separate men's and women's heat and water facilities, booked by appointment.

Las Vegas, Nevada

An adults-only hotel spa inside Encore Las Vegas with whirlpool, sauna and steam room, open daily for treatments and day passes, walk-ins welcome.

Atlanta, Georgia

Hotel spa inside the Four Seasons Atlanta in Midtown, open to guests 16 and up for massages, facials and a heated saline pool with sauna and steam room.

Denver, Colorado

A hotel spa in downtown Denver with a $150 day pass covering pool, steam room, whirlpool and fitness centre access, open to non-guests.

Houston, Texas

A Four Seasons hotel spa in downtown Houston with three treatment rooms, a couples' suite and rooftop pool access, open to day-pass guests.

Milan, Lombardy

A luxury hotel spa inside Four Seasons Hotel Milano with a 14-metre pool under a vaulted ceiling, sauna, gym and private suites for couples' treatments.

New York City, New York

A 30-treatment luxury hotel spa in Lower Manhattan with a lap pool, steam rooms and the German GREEN PEEL facial as its signature service.

Philadelphia, Pennsylvania

A 57th-floor hotel spa in Center City Philadelphia with an infinity-edge pool, 11 treatments, and a day pass that pairs pool access with a service.

Washington, D.C., District of Columbia

Hotel spa at Four Seasons Washington, DC with a private contrast therapy room, pool, and an adults-only, couples-friendly treatment menu.

Nashville, Tennessee

A hotel spa in downtown Nashville with six treatment rooms, a rooftop infinity pool, and day passes open to non-guests.

Bora Bora

A hotel spa at Four Seasons Resort Bora Bora with glass-floor treatment suites over the lagoon, limited to resort guests.

Palm Beach, Florida

A Forbes Five-Star resort spa in Palm Beach offering 22 treatments, a eucalyptus steam room, saltwater whirlpool, and day-pass access.

Vail, Colorado

A hotel spa at Grand Hyatt Vail with three treatments, an outdoor heated infinity pool, hot tubs and cold plunges along Gore Creek.

Vail, Colorado

A day spa and recovery club in downtown Vail with hot tub, sauna, steam room, cold plunge and salt lounge, plus day passes and fitness access.

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.

Jackson Hole, Wyoming

A hotel spa in downtown Jackson Hole for hotel guests only, with seven treatment rooms, sauna, rooftop hot tub and a fitness center.

Park City, Utah

A hotel spa in Park City with seven treatment rooms, hydrotherapy tub and steam rooms, open to guests by reservation, minimum age 16.

Miami, Florida

A two-room hotel spa on the 8th floor of Loews Coral Gables, open daily 10am-6pm for massages, facials and salon services, hotel guests only.

Boston, Massachusetts

A luxury hotel spa in Boston's Back Bay with a Crystal Steam Room, Vitality Pool and private couples suites, open to adults 18 and over.

Las Vegas, Nevada

Hotel spa on the Palms casino level in Las Vegas with steam rooms, saunas, a seasonal pool and 32 treatments including massage, facials and body work.

San Diego, California

Resort spa on Mission Bay offering massages, facials and body treatments, with walk-ins welcome and a gym and yoga classes on-site.

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.

Killarney, Munster

Hotel spa and leisure studio at The Killarney Park with a 20m pool, outdoor jacuzzi, sauna and steam room, open to hotel guests only.