Spas with upscale

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.

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.

Sedona, Arizona

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

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.

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.

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.

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.

Catskills, New York

A Catskills retreat center with a Tibetan-style spa offering sauna, steam, pools and cold plunge, built around overnight stays and group programs.

San Diego, California

A hotel spa on Mission Bay in San Diego with sauna, steam room, cold plunge and thermal pools, open only to resort guests.

Adairsville, Georgia

A resort spa at Barnsley Resort in Adairsville, Georgia, offering massage, facials, reflexology, sauna and steam room, open to hotel guests only.

Ein Bokek, Southern District

A large hotel resort spa in Ein Bokek with two spa facilities, a thermal pool and 606 rooms overlooking the Dead Sea, open to hotel guests only.

Scottsdale, Arizona

A hotel spa at the 65-acre Fairmont Scottsdale Princess resort in North Scottsdale, open to overnight guests with sauna, steam room and pool access.