Spas with moderate

Carson, Washington

A clothing-optional, adults-only mineral hot springs bathhouse in Carson, Washington, with a $12 day pass and a $30 bath-and-wrap treatment.

San Diego, California

Hotel spa at the Catamaran Resort in Pacific Beach, San Diego, with a bay-view hot tub, pool and restaurant, open to hotel guests only.

Incheon

Cimer is a Korean spa in Unseo-dong, Jung-gu, Incheon, open daily 10am–9pm with a pool and walk-in access.

Many, Louisiana

Hotel spa at Cypress Bend Resort on Toledo Bend Lake in Many, Louisiana, with a sauna, hot tub, and heated indoor and outdoor pools.

San Diego, California

Hotel wellness facilities at the DoubleTree Del Mar in Carmel Valley, San Diego, with a sauna, steam room, outdoor pool and fitness center for hotel guests.

Riviera Maya, Quintana Roo

Resort spa at the Fiesta Americana Cozumel with sauna, steam room, cold plunge and couples treatments, open to hotel guests only.

Lake Tahoe, California

A wellness studio in Tahoe City offering reiki, massage, meditation, sound healing and yoga classes, open daily from 9am to 7pm.

Mývatn, Northeastern Region

A 92-room hotel at Lake Mývatn with an in-house sauna for overnight guests only; no day-pass access.

Lake Tahoe, California

A resort spa inside Granlibakken's mountain lodging complex near Tahoe City, open to hotel guests with a pool, hot tub and yoga space on site.

Termas de Río Hondo, Santiago del Estero

An all-inclusive family resort in Termas de Río Hondo with thermal pools, a spa and buffet dining, open to hotel guests only.

San Diego, California

A hotel spa at the Handlery Hotel in Mission Valley, San Diego, with sauna, steam room, cold plunge and thermal pools for guests.

Calistoga, California

A clothing-optional hot springs retreat outside Calistoga with eight mineral pools, spa bodywork, and day-pass, camping, and lodging options.

Miami, Florida

A hotel spa in downtown Miami with a day pass covering sauna, steam, cold plunge and thermal pools, plus 13 treatments on the menu.

Karjalohja, Uusimaa

Lakeside resort spa on Lohjanjärvi in Karjalohja, about an hour from Helsinki, with a day pass, thermal pool, salt room and restaurant.

Las Vegas, Nevada

Float tank, massage and salt therapy spot in Peccole Ranch, Las Vegas, open daily with walk-ins accepted alongside bookings.

Dobbs Ferry, New York

A Dobbs Ferry day spa with a hydrotherapy circuit, relaxation lounge, massages and facials, open daily with reservations recommended.

Santa Fe, New Mexico

A downtown Santa Fe day spa and oxygen bar offering massage, energy work and blessing ceremonies alongside an on-site apothecary restaurant and wellness shop.

San Francisco, California

An adults-only bathhouse in San Francisco's Tenderloin with a thermal pool and an on-site restaurant, open daily except Tuesdays.

Naples, Florida

Day spa in Central Naples with a salt cave for halotherapy, plus massage, facials and yoga classes; walk-ins welcome but reservations recommended.

Pamukkale, Denizli

A 315-room thermal resort in Karahayıt near Pamukkale with its own thermal pools, pine-shaded gardens and on-site dining, open to hotel guests only.

Carmel-by-the-Sea, California

A hotel spa inside Carmel-by-the-Sea's Hyatt Regency Monterey property, with hydrotherapy, sauna and a relaxation lounge for guests and couples.

Boston, Massachusetts

Day spa in East Boston offering massages, facials, body care and a hydrotherapy circuit, open daily except Sunday with walk-ins welcome.

Lake Tahoe, California

A lakefront lodge in South Lake Tahoe where guest wellness amenities are a pool, hot tub and private beach rather than a treatment spa.

Ourense, Galicia

An outdoor hot-springs spa in Ourense with thermal pools, walk-in day passes, and hours that run late on weekends.