Surrounded by Napa Valley vineyards and oaks, Calistoga Ranch, run by the company behind nearby Auberge du Soleil, is like a summer camp for pampered adults, with copper-trimmed cedar cabins serving as stylish bunkhouses. No cars are allowed on the 157-acre property, so guests—including robed couples en route to the Bathhouse spa— are escorted about in golf carts. Morning yoga takes place in the wine cave, and after a soak in a mineral pool, guests keep warm under handwoven chenille throws in front of outdoor fireplaces. Staff will pour you an in-room tubful of the restorative mud that has been drawing wellness seekers to the area for 150 years. If you are feeling squeamish, try the 90-minute Cabernet Classic, a grapeseed scrub and grapeseed-oil massage that makes creative use of the Valley’s most famous crop.