Spas with upscale

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.

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.

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.

Chicago, Illinois

Adults-only hotel spa inside JW Marriott Chicago offering massages, facials, nail services, an indoor pool and steam room, open 8am-8pm daily by appointment.

Taipei

Hotel spa in Taipei's Songshan district with private suites, sauna, steam room and a heated outdoor pool, open daily with day passes for non-guests.

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.

Killarney, Munster

A hotel spa in Killarney National Park with an adults-only Vitality Suite of hydrotherapy pool, sauna, steam room and outdoor hot tub.

Napa Valley, California

Adults-only hotel spa in downtown Napa with thermal circuits, sauna, steam and cold plunge, plus massages, facials and medical aesthetics.

Palm Beach, Florida

A 40,000-square-foot day spa at PGA National Resort in Palm Beach Gardens, open to the public, with mineral pools, steam, sauna and a $100 treatment minimum

Chicago, Illinois

A 5th-floor day spa inside the Palmer House Hilton in the Loop, built around a hydrotherapy circuit, Vichy shower treatments and a facial called Glow Revival.

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.

Calistoga, California

A 20,000-square-foot resort spa in Calistoga with five geothermal pools, Calistoga mud treatments, and a day pass 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.

Sun Valley, Idaho

Resort spa at Sun Valley Lodge in Idaho offering massage, skincare, salon and nail services plus outdoor pools, open daily 8am-6pm for hotel guests.

Asheville, North Carolina

Adults-only hotel spa in Asheville with a fiber-optic-starred lap pool, waterfall pools, saunas and an electronics-free policy; day passes are limited and

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.

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.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Philadelphia, Pennsylvania

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

Aix-les-Bains, Auvergne-Rhône-Alpes

Medical thermal baths in Aix-les-Bains treating respiratory and oral mucosal conditions with sulfur-rich water, mostly through prescribed multi-day cures.

Taos, New Mexico

A reservation-only wellness studio in Taos offering hyperbaric oxygen, colon hydrotherapy and infrared sauna sessions aimed at altitude recovery.

Key West, Florida

A medical spa in Key West offering Morpheus8, injectables and body contouring, with a sauna, steam room and thermal pool on site by appointment only.