Spas with fitness center

Portorož, Coastal-Karst

Thermal baths and seawater pools in Portorož, open daily 7am–9pm with walk-in day passes and a large sauna park.

Boston, Massachusetts

A luxury hotel spa in Boston's Back Bay with a Crystal Steam Room, Vitality Pool and private couples suites, open to adults 18 and over.

Taipei

Hotel spa in Taipei's Songshan district with private suites, sauna, steam room and a heated outdoor pool, open daily with day passes for non-guests.

Palm Beach, Florida

A 40,000-square-foot day spa at PGA National Resort in Palm Beach Gardens, open to the public, with mineral pools, steam, sauna and a $100 treatment minimum

San Diego, California

Adults-only day and hotel spa in Rancho Bernardo with gardens, whirlpools, a steam room and an 18-treatment menu, open daily 9am-6pm.

Calistoga, California

A 20-treatment hotel day spa in Santa Rosa with an indoor caldarium plunge pool, eucalyptus steam rooms, and walk-in or reserved day passes for adults 18+.

Whistler, British Columbia

Hotel spa at the Westin in Whistler Village with 19 treatments, couples massage, and free access to the hotel's pools, sauna, steam room and gym.

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.

Philadelphia, Pennsylvania

Korean-style bathhouse in Cheltenham, just outside Philadelphia, with themed heat rooms, scrub and massage services, and a fitness center.

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.

Santa Fe, New Mexico

A Santa Fe day spa combining yoga, pilates and nia classes with spa treatments, a café and a boutique, open daily 9am–7pm.

Taos, New Mexico

A moderate-priced day spa at Taos Ski Valley with a heated pool, hot tubs, steam rooms and a day pass open to non-hotel guests.