Spas with overnight stay

Calistoga, California

A historic hot-springs resort in Calistoga with an early-1900s mineral pool, mud baths, and a public restaurant, but spa access is limited to hotel guests.

Tulum, Quintana Roo

A boutique hotel resort in Tulum's Aldea Zama with two pools, a yoga terrace and a rooftop restaurant, open to overnight guests rather than day visitors.

San Juan

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.

Austin, Texas

Adults-only resort spa on Lake Austin offering all-inclusive overnight stays and limited day passes to pools, saunas, steam rooms and lake activities.

Hudson Valley, New York

Resort spa at Mohonk Mountain House with a steam room, sauna and outdoor heated mineral pool, open to overnight guests and day-pass visitors.

Berkshires, Massachusetts

A lakeside resort in Egremont with a seasonal pool and sauna for overnight guests only; no day passes and no spa treatments on offer.

Scottsdale, Arizona

A hotel spa at Scottsdale Camelback Resort, open only to resort guests staying in the property's villas at the base of Camelback Mountain.

Scottsdale, Arizona

An adults-only hotel spa in Old Town Scottsdale with sauna, steam room, cold plunge and thermal pools, open to hotel guests 21 and up.

The Hamptons, New York

Adults-only destination spa and 12-room retreat in Water Mill, offering hydrotherapy, yoga, spa treatments and overnight stays by reservation.

Lake Tahoe, California

Hotel-only spa at a lakefront resort in South Lake Tahoe, with an outdoor heated pool, Jacuzzi and treatment rooms aimed at couples.

East End, St. Thomas

Hotel spa inside a 30-acre oceanfront Ritz-Carlton resort on St. Thomas's East End, with a $450 day pass for pool and outdoor bath access.

Miami, Florida

A large hotel wellness resort on North Beach with a European-style hydrotherapy circuit, cryotherapy, acupuncture and an oceanfront fitness center.

Naples, Florida

A hotel-guests-only resort spa at Naples Grande Beach Resort in North Naples, open daily 9am-5pm, with pool and ocean-view access.

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.

Ubud, Bali

A 22-acre riverine-forest wellness retreat outside Ubud built around a sacred spring, accessible only to guests staying at the estate.

Miami, Florida

A hotel spa and pool deck at a beachfront DoubleTree in North Miami Beach, open to overnight guests with sauna, steam room and fitness center.

Santa Fe, New Mexico

Hotel spa at the 65-room Four Seasons Rancho Encantado Santa Fe, open to resort guests with couples treatment rooms and a private courtyard.

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.

Boston, Massachusetts

A hotel spa inside Mandarin Oriental, Boston's Back Bay property, open to hotel guests only, with sauna, steam room, pools and a cold plunge.

Ramona, California

A vacation-rental resort in Ramona whose day-spa access, sauna, steam room and heated pool are reserved for guests staying on the property.

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

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.