Spas with hot tub

Temescal Valley, California

Adults-only hot springs resort in Temescal Valley with 19 outdoor mineral pools, red clay baths, and a cave-like grotto, open daily 9:30am-5pm.

Calistoga, California

A Calistoga hot springs spa built around mud baths, with private couples rooms and mineral pools open daily from 8am to 11pm.

Vail, Colorado

Hotel spa and recovery club in Vail Village with hot tubs, cold plunge, sauna, salt room and a gym, open to day-pass visitors.

Doha

Hotel spa at The Westin Doha with some of the city's largest wet facilities, accessible to hotel guests and members only, no day passes sold.

Nashville, Tennessee

A Finnish-inspired bathhouse and salon in a converted East Nashville factory, with sauna, steam room, cold plunge and private suites for couples.

Opatija, Primorje-Gorski Kotar

A 5-star hotel spa in Opatija with a sauna centre, seawater pools and couples treatments, open only to Hotel Ambasador guests.

Krynica-Zdrój, Lesser Poland

Mountain resort spa in Krynica-Zdrój with indoor and outdoor pools, a sauna complex, and a clothing-optional 18+ zone; day passes available.

Velingrad, Pazardzhik

Hotel spa in Velingrad with mineral-water pools, saunas, steam rooms and a hammam spread over 4,000 square metres; day passes are available.

Houston, Texas

Upscale day spa at The Houstonian in Houston with 22 treatment rooms, soaking pools and a sundeck; pool access comes with a 50-minute-plus treatment, not a

Bük, Vas

Hotel spa in Bükfürdő with pool, jacuzzi, saunas and massage services, open to guests staying in either of its two linked wings.

Beppu, Oita

A hot-spring bathhouse in Beppu's Kannawa district, running since 1922 on 100% unblended spring water with walk-in day passes.

Miami, Florida

A co-ed Turkish hammam and day spa in North Miami offering a $125 day pass with saunas, steam rooms, a hydromassage pool and an on-site Turkish restaurant.

New York City, New York

A 24-hour Korean jjimjilbang-style day spa in Midtown Manhattan with saunas, a soaking tub, and a $135 body-scrub signature treatment.

Bursa

A historic thermal bathhouse and small hotel in Bursa's Kükürtlü district, with separate men's and women's hamams, day passes, and overnight stays.

San Diego, California

A walk-in day spa in San Diego's Hillcrest neighborhood with massage, cryotherapy, salt therapy and a $100 all-day wellness pass.

Bishop, California

A century-old natural hot springs pool near Bishop in the Eastern Sierra, with a cooling waterfall, a separate hot soak, and simple day-use facilities.

Portland, Oregon

A membership-driven wellness club in downtown Portland with hot pools, sauna, steam room and cold plunge, plus massage, skincare and fitness classes.

Chicago, Illinois

Day spa in Burr Ridge, about 20 miles outside Chicago, built around a hydrotherapy circuit with whirlpool, cold plunge and steam room.

Orlando, Florida

Family resort near Walt Disney World with a pirate-themed pool complex and a spa offering day passes and couples treatments.

Ein Bokek, Southern District

Hotel spa on the Dead Sea shore in Ein Bokek with a heated mineral-water pool, sulphur pools, hammam and sauna; day passes open to adults 16 and up.

Santa Cruz, California

A communal hot-tub and sauna garden in Santa Cruz, modeled on a Japanese bathhouse, with day passes, private rooms, and massage add-ons.

Pärnu, Pärnu County

A 193-room medical spa hotel in Pärnu with a pool and sauna complex, salt therapy, physiotherapy and water aerobics, open to day visitors.

Napa Valley, California

A family-run day spa in Vacaville near Napa Valley, offering massage, facials, waxing and a private whirlpool tub by appointment only since 1997.

New York City, New York

A Flushing, Queens bathhouse open 8am-11pm daily, with wet and dry saunas, hot tubs, exfoliating treatments and a restaurant, $40 day pass.