Spas with fitness center

Vail, Colorado

Hotel spa at the Westin Riverfront in Avon near Vail, with 14 treatment rooms, a saline lap pool, three infinity hot tubs and day passes for non-guests.

Buenos Aires

A hotel spa at the Four Seasons Buenos Aires with day passes, seven treatments including a tango-inspired massage, plus pool, sauna and steam room.

Santa Barbara, California

A 42,000-square-foot hotel spa in Santa Barbara with an adults-only pool, redwood sauna, eucalyptus steam room, cold plunge and rooftop terrace.

Los Angeles, California

Downtown LA hotel spa at the Ritz-Carlton with massages, facials, a couples suite, rooftop pool and gym; outside guests need to book a treatment to enter.

Naples, Florida

Hotel spa at The Ritz-Carlton, Naples with 23 treatments, steam rooms, plunge pool and separate men's and women's lounges, open daily 9am–6pm.

Chicago, Illinois

A hotel spa inside Four Seasons Chicago, Streeterville, with an indoor infinity-edge pool, whirlpool and fitness centre, open on a day-pass basis.

Los Angeles, California

Four Seasons hotel spa in Beverly Hills with a steam room, rooftop pool, fitness center and eight treatments, open daily, day passes available.

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.

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.

Los Angeles, California

A fourth-floor hotel spa at Four Seasons Los Angeles with sauna, steam room, fitness center and a CBD-focused signature massage, limited to hotel guests.

Bora Bora

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

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.

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.

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.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

Hua Hin, Prachuap Khiri Khan

Hotel spa at The Standard, Hua Hin, offering 11 treatments, ice bath therapy, and a day pass option at a beachfront resort on Naresdamri Road.

Philadelphia, Pennsylvania

Hotel spa in Center City Philadelphia with a heated indoor saltwater pool, fitness center and day-pass access for non-guests.

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Miami, Florida

A 20th-floor hotel spa in Downtown Miami's JW Marriott Marquis offering massages, facials, body treatments and separate men's and women's lounges.