Spas with upscale

Lake Tahoe, California

An adults-only hotel spa at the Everline resort in Olympic Valley, open to day visitors and hotel guests Thursday through Sunday.

Asheville, North Carolina

A reservation-only, adults-only spa inside Grand Bohemian Lodge in Biltmore Village, open to hotel guests only.

Orlando, Florida

A hotel spa inside the Hyatt Regency Orlando conference hotel on International Drive, open daily for guests only.

Las Vegas, Nevada

A 17,000-square-foot hotel spa in Las Vegas with 15 treatment rooms, a fitness center and a yoga studio, open to Palms guests daily.

Carmel-by-the-Sea, California

A hotel spa at Sanctuary Beach Resort in Marina, with three treatment rooms, a relaxation lounge and an outdoor deck looking over the dunes and Pacific.

Napa Valley, California

Adults-only resort spa in Napa Valley with pools, sauna, steam and a fitness center, open to hotel guests and club members via day pass.

Scottsdale, Arizona

Adults-only resort spa inside Talking Stick Resort in Scottsdale, open daily with couples-friendly treatment rooms and day-pass access for hotel guests.

Edinburgh, Scotland

Hotel spa inside The Caledonian on Princes Street with a thermal pool, sauna, steam room and relaxation lounge, open daily 6am to 9pm.

Denver, Colorado

A hotel spa inside The Inverness resort in Englewood near Denver, open daily with a relaxation lounge, limited to hotel guests.

Las Vegas, Nevada

Hotel spa at Virgin Hotels Las Vegas with massages, skin treatments, a Roman-style bathhouse, relaxation lounge and thermal pool, open to hotel guests.

Palm Springs, California

A resort spa in Desert Hot Springs, near Palm Springs, built around natural hot mineral pools, open daily from 8am to 9pm for day-pass visitors and hotel

Houston, Texas

Thompson Spa is a hotel spa in Houston's Fourth Ward open only to hotel guests, with reservations required and an adults-only, couples-friendly setting.

Washington, D.C., District of Columbia

A hotel spa inside the Waldorf Astoria on Pennsylvania Avenue NW, open daily with adults-only access and both day-pass and guest-only policies listed.

Atlanta, Georgia

An adults-only hotel spa in Buckhead with private treatment suites and a relaxation lounge, open daily with a day-pass option.

Guerneville, California

Hotel spa at West Sonoma Inn & Spa in Guerneville, open to overnight guests for massages, facials and a vineyard-view lounge.

Tucson, Arizona

A hotel spa at an 80-acre Sonoran Desert resort in Tucson, open to overnight guests, with three pools, hot tubs, sauna and yoga classes.

Scottsdale, Arizona

A skincare-focused day spa in South Scottsdale offering facials and treatments using SkinBetter and GlyMed product lines, open weekdays by appointment.

Sedona, Arizona

Hotel spa at Hilton Sedona Resort at Bell Rock offering day passes with a relaxation lounge, steam room, sauna and thermal pool, open daily 6am-8pm.

Houston, Texas

A hotel spa inside The Laura Hotel in downtown Houston offering massage, facial and nail treatments for solo visitors, couples and groups.

Buxton, England

A hotel spa built into Buxton's historic Crescent, centred on a thermal pool, hydrotherapy circuit and salt room, open to hotel guests only.

Scottsdale, Arizona

A hotel spa at Caesars Republic Scottsdale in South Scottsdale with sauna, steam room and pool, open to hotel guests only.

Dead Sea, Balqa

A hotel resort spa on the Dead Sea shoreline in Sweimeh, with massage treatments, two infinity pools and a rooftop bar, open only to hotel guests.

Sedona, Arizona

Hotel spa near Bell Rock in Sedona with sauna, steam room, cold plunge and pools, open to resort guests only.

Riviera Maya, Quintana Roo

A resort spa inside the all-inclusive Iberostar Waves Cozumel beach hotel, open to day-pass visitors as well as overnight guests.