Spas with reservation required

Barcelona, Catalonia

Adults-only thermal baths in a converted 18th-century building near Barcelona's Born market, with soaking pools, massages and couples rituals.

Längenfeld, Tyrol

A large thermal bath and 4-star hotel spa in the Ötztal valley near Längenfeld, with indoor-outdoor pools, a sauna garden and a dedicated kids' water world.

Daylesford, Victoria

A rammed-earth house on 80 hectares near Daylesford, rented whole for up to 10 adults, with in-room massage and a two-night minimum stay.

Seattle, Washington

A private floating bathhouse on Seattle's Lake Union, booked out entirely for one group of up to 12 for sauna, cold plunge and hot tub rounds.

Austin, Texas

Medical spa and day spa on South Lamar offering facials, injectables, massage and a signature $1,499 Mermaid Lift, open daily with private rooms and a stocked

Glenwood Springs, Colorado

A reservation-only tub house in Glenwood Springs built around Czech-style beer baths, with infrared sauna and private rooms for solo soaks or couples.

Sacramento, California

Day spa in Sacramento's Oak Park with float rooms, private cold plunge and sauna suites, infrared sauna, and a Somadome meditation pod.

Istanbul

A working Ottoman hammam built in 1741 in Istanbul's Fatih district, offering traditional bath rituals with no day-pass option, only full treatments.

Medellín, Antioquia

Day spa in a rooftop wellness area at the Celestino Hotel in El Poblado, with sauna, steam room, jacuzzi, cold plunge and massage treatments.

Charleston, South Carolina

A West Ashley day spa in Charleston focused on scalp and hair treatments, with the $165 Signature Head Spa as its main draw.

Marrakech, Marrakesh-Safi

A 1,200-square-metre hotel spa at Selman Marrakech built around the Chenot method, with hammams, pools and multi-day wellness programmes.

Hot Springs, Arkansas

A combined day spa and med spa in Hot Springs offering massages, facials, laser treatments and lunch-inclusive packages by reservation.

Los Angeles, California

A Glendale day spa offering massage, facials, waxing and nail care, plus private jacuzzi-and-sauna suites, open daily 9am to 9pm with walk-ins welcome.

Carmel-by-the-Sea, California

Day spa inside Casa Munras Garden Hotel in Monterey, open daily 10–6, with sauna, soak baths and a couples suite.

Miami, Florida

Hotel spa inside Dua Miami, Autograph Collection in Brickell, open daily 9am-6pm, with sauna, steam room, cold plunge and couples massage rooms.

Austin, Texas

A Japanese-style head spa in North Austin's Jollyville area offering an ASMR scalp shampoo massage in private, two-person or group suites by appointment.

Austin, Texas

A North Austin head spa near The Domain built around Japanese-style scalp massage, with private, couples and group suites by appointment.

Penang

Day spa in George Town offering Thai massage, foot reflexology and full body treatments in private rooms, open daily 11am to midnight.

Durango, Colorado

A hot springs resort in the Animas Valley near Durango, Colorado, with 32 mineral pools, cold plunges, a lap pool and private cedar soaking tubs.

Palm Springs, California

Moroccan-themed inn in Desert Hot Springs with natural mineral hot springs, a spring-fed pool and day-pass access from 9am to 4pm.

Madrid, Community of Madrid

Small Japanese-inspired onsen spa in central Madrid with a wooden hot tub, Finnish sauna and massage menu, open daily for day passes.

San Diego, California

A budget-friendly day spa in downtown San Diego offering Thai, Swedish and deep-tissue massage plus a sauna and hot tub package for solo visitors and couples.

Palm Springs, California

Hotel spa inside the Avalon in Palm Springs, open Thursday through Monday, with a $75 day pass covering jacuzzi, sauna, cold plunge and steam rooms.

Nashville, Tennessee

A Brentwood day spa focused entirely on scalp and head treatments, with private suites and a signature ritual built around halo water therapy.