It’s a place to have a spa day fit ... under a pile of volcanic ash, officials said Friday. The luxurious private complex, called a once-in-a-century find, featured baths with hot, warm and ...

Calistoga Spa Hot Springs offers everything from volcanic ash mud baths to nighttime swims in geothermal pools. For a Tuscan-inspired spa getaway, opt for the Roman Spa Hot Springs Resort.