Spas with day pass

Bath, England

Adults-only thermal spa in central Bath with a naturally warm mineral rooftop pool, open daily 9am–9pm with walk-in day passes.

Eger, Heves

An indoor-outdoor thermal bath complex in Eger with sulfur and radon pools, a kids' pool, slide pool and adult adventure pool, open daily 10am-6pm.

Dax, Nouvelle-Aquitaine

Family-run thermal hotel in Dax with a supervised pool, sauna, hammam and a 20-treatment mini-cure over five days, plus day-pass access to the spa.

Palm Springs, California

A 16-room adults-only hotel in Desert Hot Springs with three natural mineral-water pools fed by a 350-foot geothermal well, plus a small on-site spa and

Rogaška Slatina, Savinjska

Wellness center at Grand Hotel Rogaška in Rogaška Slatina, Slovenia, with pools, saunas and fitness; day pass available by reservation.

Rotorua, Bay of Plenty

A lakefront resort spa in Holdens Bay, Rotorua, with day passes, jacuzzis, sauna and an onsite restaurant, open daily 8am-9pm.

Taupo, Waikato

Adults-only geothermal hot springs in the Wairakei valley near Taupo, with three thermal pools fed by natural silica-rich mineral water, plus spa treatments

Auckland

A family-run rainforest resort in the Waitakere Ranges near Auckland offering a day spa, private yoga and free hiking and biking trails.

Scottsdale, Arizona

Adults-only hotel spa at the Fairmont Scottsdale Princess with a rooftop pool, grotto waterfall pool, sauna, steam room and cold plunge, open daily 6am-7pm.

Los Angeles, California

A 24-hour Korean jjimjilbang on Wilshire Blvd in Westlake with single-sex bathing floors, a family-friendly sauna level and a rooftop terrace.

Nashville, Tennessee

Upscale day spa in Franklin outside Nashville offering facials, massages, a salt room, infrared sauna and hydrotherapy tub, open daily by reservation.

New York City, New York

A Brooklyn bathhouse built around the largest banya in the US, with Turkish and Moroccan hammams, multiple saunas and a hydrotherapy pool circuit.

The Colony, Texas

A day-soaking spa in The Colony with mineral pools at varying temperatures, seven saunas, cold plunges and a poolside café.

Yalova

Historic Ottoman-era thermal baths in Yalova's Termal district, with day-pass access to pools and private bath cabins.

Palm Springs, California

Adults-only clothing-optional resort in Desert Hot Springs with mineral water pools, whirlpools, a nude cedar sauna and day-pass access.

Tel Aviv, Tel Aviv District

Hotel spa inside Hotel Drisco Tel Aviv on Ben Yehuda Street, with rooftop baths, a Jacuzzi and couples' treatment rooms.

Hakone, Kanagawa

Small day-use hot spring bathhouse in Yumoto, Hakone, drawing from seven natural sources including one of the area's oldest, with an outdoor bath.

Carefree, Arizona

A 20-plus-acre desert wellness resort in Carefree, Arizona, with a full spa, pools, and 100-plus weekly fitness and mindfulness classes open to day visitors by

San Diego, California

A La Jolla medical spa specializing in lymphatic drainage, colon hydrotherapy and detox treatments, open since 1993, adults only, by reservation.

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.

Húsavík, Northeastern Region

Geothermal seawater baths built into the cliffs above Skjálfandi bay in Húsavík, with walk-in day passes and views toward the Arctic horizon.

Ginzan Onsen, Yamagata

A riverside hotel spa in Ginzan Onsen with a thermal bathing pool, overnight stay and day-pass access for non-guests.

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.

Thatcher, Idaho

A riverside hot springs in Thatcher, Idaho, with outdoor thermal pools, day passes, and overnight stays in yurts, cabins, or tents.