Spas with outdoor baths in California

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.

Adults-only resort spa built into a wine cave in Napa, with a vineyard-view pool, sauna, steam room and hot tub; reservations required.

An outdoor heated pool and jacuzzi at this Aloft hotel in Dublin, California, available to guests staying on-site.

Hotel wellness facilities at the DoubleTree Del Mar in Carmel Valley, San Diego, with a sauna, steam room, outdoor pool and fitness center for hotel guests.

A hotel wellness facility at InterContinental San Diego with an outdoor pool, sauna, steam room and fitness center, open to hotel guests only, ages 18+.

Adults-only hotel spa in Carlsbad with steam room, separate men's and women's lounges, and couples massage as its signature treatment.