Spas with overnight stay

New York City, New York

Korean-style day spa in Edgewater, NJ, with saunas, thermal pools and an infinity pool, open daily 9am–9:30pm, day passes for walk-ins.

Archena, Murcia

Thermal spa resort in Archena, Murcia, with a 3,000m² thermal circuit, outdoor baths and a day pass from €23.

Mendocino, California

A redwood hot tub and sauna spa in Mendocino village, offering massage and private soaks mainly for guests of the adjoining Sweetwater Inn.

Sárvár, Vas

A large thermal and wellness complex in Sárvár with indoor and outdoor medicinal pools, slides, a sauna world, fitness center and massage treatments.

New York City, New York

Korean jjimjilbang-style spa in Manhattan with saunas, steam room, soaking tub and body scrubs, open daily 8am-11:30pm on a day-pass basis.

Hua Hin, Prachuap Khiri Khan

Hotel spa at The Standard, Hua Hin, offering 11 treatments, ice bath therapy, and a day pass option at a beachfront resort on Naresdamri Road.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Auckland

A family-run rainforest resort in the Waitakere Ranges near Auckland offering a day spa, private yoga and free hiking and biking trails.

Naples, Florida

A boutique hotel in downtown Naples with a heated outdoor pool, whirlpool spa and cabanas, open only to overnight guests.

Puerto Vallarta, Jalisco

A hotel spa inside the beachfront Buenaventura Grand Hotel in Puerto Vallarta, open to resort guests for massage and relaxation between beach days.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Hilton Head Island, South Carolina

Hotel spa inside an oceanfront Hilton Head resort, offering massages, facials, body treatments and manicures to overnight guests.

Brežice, Posavje

A large thermal water park in Brežice, Slovenia, with a year-round indoor pool riviera, an adults-only sauna zone, and seasonal outdoor slides.

Rishikesh, Uttarakhand

An upscale riverside resort 18 km outside Rishikesh with an in-house spa, yoga studio and restaurant, open only to overnight guests by reservation.

Phoenix, Arizona

An all-suite Phoenix resort where the spa menu comes bundled with a 7-acre water park, but access is limited to hotel guests.

Salalah, Dhofar

A hotel-guest-only health club at Belad Bont Resort in Salalah with sauna, jacuzzi, steam bath, treatment rooms and a separate ladies-only facility.

Băile Herculane, Caraș-Severin

Hotel-based thermal spa in Băile Herculane with sulfur mineral baths, indoor and outdoor pools, jacuzzi and sauna, open to hotel guests.

Băile Herculane, Caraș-Severin

A 4-star hotel in central Băile Herculane with thermal pools, saunas, balneo and physiotherapy treatments, open to overnight guests.

Leukerbad, Valais

A 30-room hotel in Leukerbad with a private thermal pool and sauna chalet, open to overnight guests only, overlooking the Gemmi massif.

Tucson, Arizona

Lakeside Spa at this 398-room desert resort in Tucson is open to hotel guests only, with two heated pools, a Jacuzzi and mountain views of Catalina range.

Hudson Valley, New York

Day spa near Wallkill and Gardiner in the Hudson Valley offering massage, skincare and energy-healing treatments, with an on-site bed and breakfast for

San Diego, California

A resort spa on a 44-acre Mission Bay island in San Diego, open to hotel guests, with sauna, steam room and pool access.

Bad Ischl, Upper Austria

A salt-and-brine thermal bath complex in Bad Ischl with indoor/outdoor pools, a sauna world, and a rooftop wellness deck at the attached hotel.