Spas with upscale

Boston, Massachusetts

Hotel spa inside the Omni Boston Hotel at the Seaport, with eight treatment rooms and a rooftop pool, open to hotel guests only.

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.

Nashville, Tennessee

Upscale Midtown Nashville day spa with sauna, steam room and cold plunge, offering massages, facials, body treatments and couples packages.

Scottsdale, Arizona

Hotel spa at the mid-century Hotel Valley Ho in South Scottsdale, with sauna, steam room and two pools, open to hotel guests only.

Chicago, Illinois

Upscale day spa in Lincoln Park, Chicago, where booking any treatment unlocks all-day access to a hydrotherapy circuit, thermal suite and outdoor terrace.

The Hamptons, New York

A medical day spa in East Hampton offering 22 botanical-based facials, massages and oncology-support treatments, open daily 10am–6pm.

Olmué, Valparaíso

A boutique lodge and spa in the Olmué valley, about 80 minutes from Santiago, with a thermal pool, outdoor baths and day passes for non-guests.

Hilton Head Island, South Carolina

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

Jackson Hole, Wyoming

Hotel spa at Snake River Lodge in Teton Village with a pool and hot tub, open daily 10am–5pm, restricted to hotel guests.

Washington, D.C., District of Columbia

Hotel spa at Pendry Washington DC - The Wharf with eucalyptus steam rooms, a heated whirlpool and an outdoor terrace pool, open daily 10am-6pm.

Oaxaca

A traditional four-door temazcal steam ceremony about 15-20 minutes outside Oaxaca city, paired with an ice-water plunge and overnight rooms.

Palm Springs, California

Boutique hotel spa in Desert Hot Springs with two natural mineral hot spring pools, day passes, and overnight rooms that include breakfast.

Philadelphia, Pennsylvania

Hotel spa on the third floor of The Rittenhouse overlooking Rittenhouse Square, with massage, facials, body treatments and a salon.

Sonoma, California

Hotel spa at The Lodge at Sonoma with an outdoor terrace, soaking pool, plunge pool and barrel sauna, open daily 9am-5pm, adults-only, reservation required.

Berlin

A saltwater thermal pool under a concrete dome near Berlin's Tempelhofer Feld, with sauna, steam room and occasional DJ nights.

Ojo Caliente, New Mexico

Historic New Mexico hot springs resort with communal mineral pools, private tubs, and day-pass soaking near Taos.

Park City, Utah

A ten-treatment-room spa inside the private Promontory Club in Park City, with a full hydrotherapy circuit of steam, sauna and cold plunge.

Sedona, Arizona

A resort spa at Amara in Sedona with outdoor baths, an infinity pool and a relaxation lounge, open only to hotel guests.

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.

Milwaukee, Wisconsin

East Town Spa in Milwaukee's Juneau Town combines a full-service salon and med spa with a thermal circuit of sauna, steam, pools and cold plunge.

Tucson, Arizona

A hotel spa inside the 1929 Hacienda del Sol Guest Ranch Resort in Tucson, offering facials, massages and body treatments to resort guests only.

Puyehue, Los Lagos

A forest resort spa in Puyehue, Chile, with volcanic thermal pools and outdoor baths, open only to hotel guests.

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.

Bursa

Hotel spa in Bursa's Çekirge thermal district, guests-only access, with a thermal pool, hamam rituals and massage packages tied to multi-night stays.