Cacahuamilpa Grottos National Park covers 1,600 hectares (nearly 4,000 acres) in Guerrero and Morelos states, about 290 kilometers (180 milles) northeast of Acapulco near Taxco. Its grottos - more than 90 "rooms" open to the public - are one of the largest cave systems in the world. The park also has a smaller grotto system and two underground rivers. The somewhat challenging 2-kilometer tour takes roughly 2 hours. The park is the most popular spelunking destination in Mexico and offers extreme sports like repelling and rock climbing.
Parque Nacional Grutas de Cacahuamilpa, Pilcaya, Mexico