Indian Springs Resort and Spa
Time Out says
A lovely hotel tucked into the Napa Valley hillside, Indian Springs stands out for its stunning pools and luxury spa. You don't have to be a hotel guest to book a treatment (though a stay here includes a personal shaded porch, outdoor flirepace, free bike rentals, bocce and shuffleboard, the list goes on), so make it a day trip regardless of where you're staying. The spa offers a simple list of high-quality treatments: massage, facials, mud baths and mineral water soaks. The mud baths are Indian Springs' most unique offering, followed by the Buddha Pond, which is essentially a relaxation/waiting room, but in an outdoor setting with chaise lounges overlooking a small pond and outdoor fireplace. On weekdays, a spa treatment gives you access to the property's pools; on weekends pool access is an extra $30. But it's worth it; both mineral pools are fed by nearby geysers and kept at temperatures between 82 and 102 degrees (depending on the season) for maxiumum soaking relaxation. One is an Olympic-sized behemonth, while another, smaller pool is for adults only; both are open until midnight so you can soak under the stars.