The classic Calistoga mud bath experience, and the one most locals will point you toward. Dr. John Wilkinson opened here in 1952, and the place has been doing volcanic ash mud baths, mineral pool soaks, and steam rooms ever since. The signature treatment is the mud bath itself: a thick mix of local volcanic ash, peat, and mineral water that heats the body deeply and leaves the skin remarkably soft.
The property was renovated and reopened as a full resort in the 2020s while keeping the old Calistoga character intact. You can book just a spa treatment or stay overnight. Either way, this is one of the genuinely distinctive things to do in the Napa Valley — mud baths are harder to find elsewhere in wine country.