The first formal archaeological excavations at the site were led by anthropologist Eliecer Silva Celis in 1981; these resulted in the declaration of the site as an archaeological park. The burial mounds were found to have been heavily affected by grave robbery, and the human remains dispersed. The central column (about 5 meters high) described by Joaquin Acosta in 1850, which apparently allowed the measuring of the sun's astronomical alignment during the equinoxes, was missing.