Thermal hot spring complex with outdoor pools and a famous cave pool reached through a short underwater tunnel — an absolute kid highlight. Admission ~230 MXN adults / 150 MXN children; towel rentals 50 MXN. The cave tunnel is ~1 meter long and easily swum by children 6+; supervise closely as the area is slippery. Arrive on a weekday; on-site restaurant serves good Mexican food (mains 130-200 MXN).

Address: Carretera San Miguel de Allende-Dolores Hidalgo Km 10

Google Maps: Click here for directions

Cost: Paid $$