Grutas de Cacahuamilpa National Park

Grutas de Cacahuamilpa is a network of limestone passages in the state of Guerrero that runs for several kilometers underground. The corridors are wide enough to walk comfortably, and the chambers open into spaces with high ceilings where stalactites and stalagmites emerge from the darkness.

A surveyor named Manuel Saenz de la Peña came across the system in 1835 while mapping the surrounding territory. A century later, in 1936, the government declared the entire site a national park to protect the formation from damage.

The name comes from Nahuatl and means "among the cacao trees," referring to the tropical plants that grow near the entrance. Today school groups and families from across the region visit to experience the underground rooms and hear their voices echo off the stone surfaces.

Guided tours run hourly from morning until afternoon and last about two hours, walking through lit sections of the network. The floor can be slippery in places, so solid shoes and a light jacket help with the cool temperature underground.

One of the larger chambers occasionally serves as a concert hall, where musicians take advantage of the natural acoustics inside the cave. Concert-goers sit on benches and listen as sound bounces back from the curved walls.