Spas with moderate

Las Vegas, Nevada

Hotel spa on the Palms casino level in Las Vegas with steam rooms, saunas, a seasonal pool and 32 treatments including massage, facials and body work.

Dallas, Texas

A day spa in Lower Greenville with a $99 custom facial or Swedish massage, couples treatments, valet parking, and a minimum age of 18.

Aspen, Colorado

Adults-only hotel spa at Viewline Resort Snowmass with a $25 day pass, steam rooms, outdoor pool and whirlpool, reservations required.

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.

Spa, Liège

Thermal baths in the town of Spa, Belgium, fed by natural mineral water, with saunas, hammams and separate textile and naturist relaxation areas.

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.

Hanoi

Day spa in Hanoi's Old Quarter with a herbal steam room, Himalayan salt stone room and jacuzzi, open daily 10am–10pm.

Los Angeles, California

Day spa in West Hollywood with wet and dry banyas, pool, sauna, cold plunge and café; day pass is $110, walk-ins welcome.

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.

Santa Fe, New Mexico

A 16,000-square-foot adults-only hotel spa at Hilton Buffalo Thunder near Santa Fe, with separate men's and women's saunas, steam rooms and whirlpools.

San Diego, California

Korean-style day spa in Kearny Mesa with red clay and salt saunas, hot and cold tubs, an ice room, and walk-in day passes.

Boston, Massachusetts

A hotel day spa at Battery Wharf in Boston's North End with a co-ed Turkish hammam, separate saunas, and fitness studios for barre and yoga.

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.

Águas de São Pedro, São Paulo

Day spa in central Águas de São Pedro offering massage, facials and couples packages, open daily except Sunday with walk-ins and day passes welcome.

Minneapolis, Minnesota

A St. Paul wellness studio in Macalester-Groveland offering infrared sauna, float tanks, salt therapy and cold plunge by reservation, adults-only, day-pass

Calistoga, California

A day spa and co-ed bathhouse in downtown Sebastopol with women-only and clothing-optional sessions on set days.

Sedona, Arizona

Day spa in Sedona with eucalyptus steam rooms, saunas, jacuzzi and a fitness center, offering day passes and memberships for walk-in guests.

Brežice, Posavje

A large thermal water park in Brežice, Slovenia, with a year-round indoor pool riviera, an adults-only sauna zone, and seasonal outdoor slides.

Seattle, Washington

A moderate-priced day spa in Northwest Bellevue built around a hydrotherapy circuit, open daily with both day-pass and membership access.

Puelo, Los Lagos

Adults-only hot springs in Puelo with ten thermal pools, a sauna, steam room and individual herbal tubs, open daily with walk-in day passes.

Houston, Texas

Westside Houston day and med spa with treatment menu plus an H-Circle membership for $99/month, open daily with day passes available.

Milan, Lombardy

Adults-only day spa in a Liberty-style building near Milan's Parco Sempione, with thermal pools, saunas, steam room and a hydrotherapy circuit.