Founded in 1952 by wellness experts “Doc” and Edy Wilkinson, this Calistoga icon recently emerged from a top to bottom renovation. All 50 guestrooms got a refresh, new open-air restaurant, House of Better opened its doors, and the space surrounding the property’s three geothermal mineral pools got gussied up with photo-worthy murals. Thanks to a long list of upgrades, the spa is barely recognizable, but the recipe for the mud bath treatments launched nearly three-quarters of a century ago, thankfully has not changed.