La Gruta Hot Springs

La Gruta Hot Springs sits along the highway between San Miguel de Allende and Dolores Hidalgo, in the volcanic-spring belt of Guanajuato state that also feeds Xote and Escondido Place nearby. The setting is a landscaped thermal park built around a series of open-air pools, but the signature feature is a domed brick tunnel that visitors wade through to reach a partially covered grotto pool lit by a skylight cut into the rock above -- the feature that gives the park its name. Water temperatures across the pools range from warm to noticeably hot, fed continuously by an underground mineral spring rather than heated mechanically. There is no dedicated treatment menu of facials or body wraps here; La Gruta is a bathing park rather than a spa, though poolside massage is available as a paid add-on from on-site therapists, and a sauna is accessible to day visitors. The mineral content of the water, similar to other springs in this stretch of Guanajuato, is associated locally with relief for muscle soreness and skin conditions, though the park makes no medical claims. Facilities include changing rooms, lockers, a snack bar, and grassed areas for resting between soaks. Entry is walk-in on a first-come basis rather than by reservation, and access is sold as a day pass covering unlimited use of the pools and tunnel; treatment add-ons such as massage are booked on-site at the treatment desk once inside. Weekends and Mexican holiday periods draw the largest crowds from San Miguel de Allende and Dolores Hidalgo, so arriving soon after the 9AM opening reduces waiting for the grotto tunnel, which has limited capacity at any one time.