Spas with upscale

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.

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.

Ibusuki, Kagoshima

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

Velingrad, Pazardzhik

Adults-only hotel spa in Velingrad with a mineral-water pool, jacuzzi and massage pool, open to overnight guests of the five-star Kashmir property.

Tucson, Arizona

Adults-only day spa in Tucson's Triangle area offering lymphatic facials, dermaplaning and a hydrotherapy circuit; reservations required.

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.

Los Angeles, California

Hotel pool and hot tub deck at a Tapestry by Hilton near SoFi Stadium and the Kia Forum in Inglewood, open to registered guests only.

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.

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.

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.

San Diego, California

Hotel spa on Shelter Island in San Diego with sauna, steam room, and pool, open to guests staying at Kona Kai Resort.

Afyonkarahisar

Resort hotel in Afyonkarahisar built around thermal pools, spa treatments and physical therapy, open to hotel guests.

Spa, Liège

Hotel spa in the town of Spa, Belgium, with a thermal pool, relaxation lounge and restaurant, open to day-pass visitors, not just hotel guests.