Spas with hotel guests only

Sapporo, Hokkaido

Natural hot spring inside Sapporo's Jasmac Plaza Hotel in Susukino, open to day visitors and hotel guests alike, with sauna and a rest lounge.

Dubai

A hotel spa inside Jumeirah Zabeel Saray on Palm Jumeirah built around a Turkish-style hammam, thalassotherapy pool and couples treatments.

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

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.

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.

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.

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.

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.

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.

Seattle, Washington

Hotel spa in downtown Seattle for Four Seasons guests, with a Himalayan salt wall, steam rooms and a six-treatment adults-only menu.

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.

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.

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.

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.

Hudson Valley, New York

A historic resort spa at Mohonk Mountain House in the Shawangunk Mountains, with a heated mineral pool, steam room, sauna and day passes for non-hotel guests.

Park City, Utah

A hotel spa at Stein Eriksen Lodge in Park City with indoor/outdoor pools, saunas and cold plunge, open to lodge guests for about eight treatments.

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.

Galway, Connacht

Adults-only hotel spa in Galway with a thermal suite, hydro pool and sauna; day pass runs about €50 and reservations are required.

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.

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.