Spas with hotel guests only

Boston, Massachusetts

Hotel spa inside Raffles Boston pairing Guerlain facials and massages with a 65-foot lap pool, hot tub, sauna, steam room and three private treatment suites.

Orlando, Florida

Adults-only luxury hotel spa at The Ritz-Carlton Orlando, Grande Lakes, with 40 treatment rooms, couples suites and a lap pool.

Vail, Colorado

Hotel spa at The Arrabelle in Lionshead Village, Vail, with 11 treatment rooms, a fitness center and locker-room steam rooms, open to hotel guests.

Jackson Hole, Wyoming

A hotel spa at Rustic Inn Creekside Resort in Jackson Hole with dry sauna, eucalyptus steam room, outdoor pool and hot tub, open to overnight guests only.

Palm Springs, California

Sante Spa is the adults-only resort spa at the Riviera Palm Springs, with 18 treatment rooms, a Watsu pool, steam room and validated valet parking.

Las Vegas, Nevada

Spa Aquae is JW Marriott Las Vegas Resort & Spa's day spa in Summerlin, with 18 treatments, couples massages and a steam room, open daily 8am-7pm.

Park City, Utah

A 27-room resort spa at Montage Deer Valley in Park City, open to hotel guests with a pool, steam room, sauna and cold plunge.

Calistoga, California

Spa Talisa is the adults-only spa at the Four Seasons Resort Napa Valley in Calistoga, with vineyard-view gardens, barrel saunas and a sunken whirlpool for

Tucson, Arizona

Adults-only hotel spa at El Conquistador Tucson with a salt therapy lounge, heated outdoor pool and mountain views, day passes available to hotel guests.

Mendocino, California

A redwood hot tub and sauna spa in Mendocino village, offering massage and private soaks mainly for guests of the adjoining Sweetwater Inn.

Tuscany

A five-star resort in the Tuscan countryside built around a natural thermal spring, with day passes from €39 for outdoor thermal pools, hydromassage circuits

Miami, Florida

A 12,000-square-foot hotel spa at Coral Gables' Biltmore, with eucalyptus steam rooms, Himalayan salt saunas and a couples suite; adults-only, reservation

Santa Fe, New Mexico

A hotel spa inside a historic adobe inn in downtown Santa Fe, with private treatment suites reserved for overnight guests only.

Scottsdale, Arizona

Hotel spa at The Phoenician in Scottsdale, open to guests 18+ who book a massage, facial, or body treatment, with sauna, steam room and a rooftop pool.

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

A hotel spa at Naples Beach Club with a 3,200-square-foot thermal circuit, rooftop lap pool and body/facial treatments built around ocean and plant themes.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

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.

Nashville, Tennessee

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

Orlando, Florida

Adults-only resort spa at Four Seasons Orlando, open daily 9am-8pm, with 12 treatments, couples' suites and access to a 21+ pool for guests booking a 50-minute

Santa Fe, New Mexico

A hotel-guests-only resort spa in Santa Fe with 15 treatment rooms, private soaking courtyards, saunas and steam rooms, built around Southwest-inspired rituals.