Spas with reservation required

Nashville, Tennessee

A Berry Hill day spa in Nashville offering massage, facials, body treatments and a sauna pod/salt room, open Tuesday through Saturday.

Piešťany, Trnava Region

Spa Irma on Piešťany's spa island offers historic mud and mirror thermal pools, a hydrotherapy circuit and a 60-treatment medical spa menu, adults only.

Los Angeles, California

A Westlake day spa built around themed sauna rooms—salt, gold, Loess soil, Elvan stone, forest and ice—plus a waterfall feature and garden.

Boca Raton, Florida

Hotel spa at The Boca Raton with 44 treatment rooms, a spa pool and waterfall whirlpools, open to resort guests, club members and day-pass visitors by

Palm Springs, California

Adults-only hotel spa at Tommy Bahama Miramonte in Indian Wells with 15 treatments, eucalyptus steam rooms, a hydrotherapy jacuzzi and saltwater pool.

Austin, Texas

Hotel spa at Hotel Viata in West Lake Hills with treatment rooms, a couples suite, pool, sauna, steam room and a day-pass option for amenity access.

Essaouira, Marrakesh-Safi

A budget hammam and day spa in Essaouira's medina offering scrub treatments, massages, hair and nail services, open daily 10am-8pm.

Seattle, Washington

Hotel spa inside the Hyatt Regency Lake Washington in Renton, offering massages, facials and body treatments alongside pool, hot tub and steam room access.

Austin, Texas

A fifth-floor hotel spa inside JW Marriott Austin with eight treatments, a heated rooftop pool and a 16-plus minimum age.

Naples, Florida

Upscale day spa in Naples offering infrared sauna, massage, facials and foot detox, with a $230 signature massage and couples packages.

Jackson Hole, Wyoming

Resort spa at Teton Village with pools, soaking tubs, a rooftop hot tub, and facials built for Jackson Hole's dry alpine air.

Los Cabos, Baja California Sur

A hotel spa at Corazón Cabo Resort offering massages, facials and a hydrotherapy circuit with sauna, steam room and hot tub, no day passes sold.

Kissimmee, Florida

A hotel spa at Margaritaville Resort Orlando in Kissimmee with massages, facials and a Himalayan salt room; open daily, walk-ins welcome.

Palm Springs, California

Hotel spa at Agua Caliente Rancho Mirage with day passes for the sauna, steam room, salt rooms and private spa pool.

Bad Wörishofen, Bavaria

Adults-only thermal baths in Bad Wörishofen with palm-house pools, mineral pools and saunas; day passes available, minimum age 16.

Philadelphia, Pennsylvania

Day spa in Cherry Hill Township near Philadelphia offering massage, head spa scalp treatments and couples sessions, open daily 9:30am to 9:30pm.

Tbilisi

A medical spa in Old Tbilisi built around natural sulfur-mineral water and volcanic mud, operating since 1938, open daily 10am–9pm.

Chianciano Terme, Tuscany

Thermal day spa in Chianciano Terme offering day passes, couples massages and a wellness-food menu, closed Thursdays and Wednesdays.

London, England

A Russian-style banya bathhouse in Belgravia offering oak-lined steam rooms, cold plunge pools and leaf-massage rituals, with day passes by reservation only.

Miami, Florida

A 12,000-square-foot hotel spa at Coral Gables' Biltmore, with eucalyptus steam rooms, Himalayan salt saunas and a couples suite; adults-only, reservation

Portland, Oregon

An 18-and-up, clothing-optional spa in Portland's Kerns neighborhood with a salt hot tub, sauna, steam room and cold plunge, reservation required.

Taos, New Mexico

Hotel day spa at El Monte Sagrado in Taos with a hydrotherapy circuit, saltwater pool and treatment rooms, open daily, day passes available.

Miami, Florida

AVEDA hotel spa at The Palms in Mid-Beach Miami, offering Ayurvedic-inspired massages, facials and salon services with pool and beach access included.

Chicago, Illinois

Luxury hotel spa in River North, Chicago, with an indoor pool, steam room and lounges, open to both hotel guests and outside bookings by reservation.