Spas with upscale

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.

Vail, Colorado

Hotel spa at The Hythe in Vail offering treatments and a relaxation lounge, open daily 9am-7pm, reservation required.

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.

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.

Park City, Utah

Hotel spa at Mayflower Mountain near Deer Valley with massages, facials, a sauna, relaxation lounge and couples treatments; reservations required.

Houston, Texas

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

Scottsdale, Arizona

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

Ibusuki, Kagoshima

A ryokan-style hotel in Ibusuki with source hot-spring baths, both shared and private, open only to overnight guests.

Karlovy Vary, Karlovy Vary Region

Adults-only resort spa on the Březová reservoir near Karlovy Vary, open to hotel guests only, with a two-floor wellness centre and outdoor baths.

Los Angeles, California

A hotel spa at Shade Hotel Redondo Beach with sauna, steam, pools, cold plunge and thermal circuits, open to hotel guests overlooking the marina.

Jackson Hole, Wyoming

Small hotel spa inside the boutique Rusty Parrot Lodge in downtown Jackson Hole, open only to overnight guests, with massage and facial treatments including

Arima Onsen, Hyogo

Hotel spa in Arima Onsen with Arima's rare iron-rich "ginsen" waters, outdoor baths, sauna and jacuzzi, run as an all-inclusive overnight stay.

Sayulita, Nayarit

A hillside boutique hotel spa outside Sayulita with sauna, steam room, cold plunge and ocean-view pool, open on a day-pass basis.

San Diego, California

Hotel spa at Carté Hotel San Diego Downtown with a heated saltwater pool, whirlpool, 28,000 sq ft fitness club with sauna and steam room, open to guests only.

Oaxaca

An all-inclusive beachfront resort spa in Huatulco with a sauna, steam room and thermal pools, open only to hotel guests.

Cancún, Quintana Roo

The spa at this all-inclusive Puerto Morelos resort offers hydrotherapy, massages and facials for hotel guests only.

Miami, Florida

A hotel spa at Eden Roc Miami Beach in Mid-Beach with sauna, steam room, cold plunge and thermal circuits, open to resort guests only.

Taos, New Mexico

A boutique skin and body studio in Taos offering facials, lymphatic massage, Endermologie and head spa treatments by appointment.

Kamijima, Ehime

An all-inclusive resort on Yugejima island in Setouchi's inland sea, with ocean-view outdoor baths, ocean-front rooms, and a day-pass option.