Archaeologists are searching for the secrets of why the ancient Mayans chose the sites for the famed pyramids of Chichen Itza by looking underground.

Mexico's Yucatan peninsula is dotted with natural wells called cenotes and underground rivers.  Archaeologists now believe that some of these hydrological features lie below the sacred ground on which the Mayan pyramids were built.

Archaeologist Guillermo de Anda from Mexico's National Institute of Anthropology and History said he and his team are looking for a Mesoamerican pattern showing a link between Mayan architecture and caves, tunnels or cenotes.

Another member of the team is James Brady from the California State University of Los Angeles, who is investigating the tunnels and passageways that lie under the pyramids.  "The great hope is to connect with the cenote under the Castillo (Pyramid)," Brady said.

The team hopes to gather enough information to construct a full 3D model of all of Chichen Itza's Mayan structures along with the geologic and hydrologic features of the ground underlying the ancient site.