Average water temperature: Bubbles up at 115°F, with pools maintaining temperatures between 85 and 106°F
Tucked into a scenic canyon in the Bradshaw Mountains just an hour from Phoenix, Castle Hot Springs has been luring tourists since the late 1800s – and Indigenous peoples for far longer – with its healing waters. Now an all-inclusive luxury wellness resort, this destination is well worth an overnight stay, thanks to exceptional stargazing at night, a thrilling onsite via ferrata course and (naturally) 24-hour access to mineral hot springs that cascade across three pools of varying temperatures.
Open to resort guests only, the geothermal hot springs here are rich in calcium and nerve-calming magnesium as well as lithium, which has been called the “happy mineral” for its mood-stabilizing properties. Take a soak surrounded by towering saguaro cacti, palms and layer upon layer of weather-worn rock, colored purple and rusty red from the spring’s mineral content.