Spas with fitness center

Hammamet, Nabeul

Seafront thalasso spa in Hammamet Est with a thermal pool, 42 treatments, and day passes open daily from 8am to 7pm.

Miami, Florida

A beachfront resort spa in North Beach, Miami with cryotherapy, a floating salt bath, sauna, steam and a cold plunge, open to walk-ins and day-pass guests.

The Hamptons, New York

Oceanfront resort spa in Montauk with a seawater and marine-based treatment menu, hydrotherapy, contrast bathing, and a heated saltwater pool.

Reykjavik, Capital Region

Eight oceanfront geothermal pools in Hvalfjörður, 45 minutes from Reykjavík, plus steam baths, a bistro and guest houses for rent.

Duluth, Georgia

A 24-hour Korean bathhouse in Duluth with a $30 day pass, sauna rooms, cold plunge, thermal circuits and a junior Olympic pool.

Edinburgh, Scotland

One Spa is an adults-only day spa in Edinburgh's city centre with a rooftop Hydropool, thermal suite and day-pass access.

Vienna

Hotel spa in Vienna's Neubau district with a 20-metre indoor pool, two saunas, a steam room and day passes for non-guests.

Vail, Colorado

A day spa and recovery club in downtown Vail with hot tub, sauna, steam room, cold plunge and salt lounge, plus day passes and fitness access.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Catskills, New York

Adults-only hotel spa in Saugerties with a day pass, pool deck, sauna, hot tub and cold plunge overlooking the Esopus Creek.

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.

Ibiza, Balearic Islands

A budget-friendly day spa in Eivissa with heated indoor pools, a hammam, sauna and ice fountain, open to walk-ins for €20.