Spas with upscale

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.

Las Vegas, Nevada

A two-floor hotel spa inside Vdara with steam room, sauna, whirlpool and lounge, open only to Vdara and ARIA guests 18 and older, closed Tuesdays.

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+.

Philadelphia, Pennsylvania

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

Brussels

Hotel spa on the 25th floor of The Hotel Brussels, with city views, sauna, steam room, salt sauna and a Technogym fitness floor.

Scottsdale, Arizona

Hotel spa inside Hotel Solaya in South Scottsdale built around Tod Miller's proprietary BodyWalking compression technique, with four treatments and a $335

Houston, Texas

Hotel spa at Hotel ZaZa in Houston's Museum District, with massages, body treatments, infrared saunas and day-pass access to the pool lounge.

Orlando, Florida

Adults-only hotel spa at the Hilton Orlando with a sauna, steam room, cold plunge and thermal pools, plus couples treatments and HydraFacials.

Lake Como, Lombardy

Hotel spa and fitness club at Hilton Lake Como in Como, open daily 9am-9pm with day passes for non-guests, adults only.

Miami, Florida

Hotel spa inside the InterContinental Miami, open daily with a day pass option, 11 treatments and a signature Raindrop Massage.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Santa Fe, New Mexico

Hotel spa at the Eldorado in downtown Santa Fe offering massage and bodywork treatments; appointments required, no day pass.

Mariánské Lázně, Karlovy Vary Region

Medical spa resort in Mariánské Lázně combining balneology, physiotherapy and Ayurveda programs, open only to overnight hotel guests aged 18+.

Las Vegas, Nevada

Adults-only hotel spa at Green Valley Ranch in Henderson, open daily 8am-8pm with day passes available to non-guests.

Sedona, Arizona

A resort spa at Amara in Sedona with outdoor baths, an infinity pool and a relaxation lounge, open only to hotel guests.

Rishikesh, Uttarakhand

An upscale riverside resort 18 km outside Rishikesh with an in-house spa, yoga studio and restaurant, open only to overnight guests by reservation.

Tucson, Arizona

A hotel spa inside the 1929 Hacienda del Sol Guest Ranch Resort in Tucson, offering facials, massages and body treatments to resort guests only.

Leukerbad, Valais

A 30-room hotel in Leukerbad with a private thermal pool and sauna chalet, open to overnight guests only, overlooking the Gemmi massif.

Bursa

Hotel spa in Bursa's Çekirge thermal district, guests-only access, with a thermal pool, hamam rituals and massage packages tied to multi-night stays.

Scottsdale, Arizona

Hotel-guests-only spa at Scottsdale's Kimpton Miralina, with sauna, cold plunge and desert-inspired massages, mud wraps and facials.

Asheville, North Carolina

Resort spa on an 85-acre Hendersonville farm near Asheville, with massage treatments in a converted horse barn, day passes, and a pool with sauna, steam and

Leukerbad, Valais

Thermal baths inside a 19th-century hotel in Leukerbad, Valais, with mineral-rich pools open daily from 9am to 8pm.

The Hamptons, New York

A membership-based wellness club in Southampton with a stadium-seating sauna, cold plunge pools, treatment suites and group classes.

Key West, Florida

A hotel spa at Pier House Resort in Key West for guests only, offering couples treatments for ages 14 and up with advance reservations.