Spas with day pass 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 hotel spa in Sausalito, California, offering day passes alongside yoga and a restaurant on site.

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