La Gruta Hot Springs
La Gruta—the Grotto—is aptly named. There are a variety of open air pools, but the star attraction is the grotto where hot water gushes from a tube high in the wall of a dark rocky cave. You approach it via a darkened tunnel, at the end of which is the cave, steamy and chest-deep in hot water. Tourists line up to get a water massage on their heads and shoulders. There's plenty to do, with restaurants, a boutique, bar, new massage wing, aromatherapy, juice bar, smallish lap pool, and large temescal (traditional Mexican steam bath) with comfortable mosaic built-ins. It's been around for decades and is one of the de rigeur places to take out-of-town guests. There are expansive lawns and lots of places to sunbathe.