Spas with relaxation lounge

Adults-only hot springs resort on Miracle Hill in Desert Hot Springs with private mineral tubs, a Finnish sauna, salt room and 35 spa treatments.

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

Adults-only spa inside the all-inclusive Ocean Riviera Paradise resort in Playa del Carmen, with sauna, Turkish bath and four treatment options via day pass.

Hotel spa at the Inn at Eagle Mountain in Fountain Hills with sauna, steam room, pools and a $69 60-minute massage as its signature treatment.

Adults-only hotel spa at El Conquistador Tucson with a salt therapy lounge, heated outdoor pool and mountain views, day passes available to hotel guests.

A 38,000-square-foot resort spa at JW Marriott Desert Springs in Palm Desert offers day passes, saunas, a saltwater lap pool and couples suites.

Adults-only resort spa in Sedona with outdoor hot tubs, steam rooms and a 30-treatment menu, open daily with walk-ins and day passes.

Adults-only hotel wellness setup in downtown Phoenix with a heated pool, sauna and steam room, day passes available for $50.

A hillside boutique hotel spa outside Sayulita with sauna, steam room, cold plunge and ocean-view pool, open on a day-pass basis.

A 25-room Sonoma hotel in Forestville with a spa barn offering sauna, steam and pools, mainly for overnight guests.