Archaeologists in Guerrero, Mexico, have discovered an unlooted 3,000-year-old Olmec astronomical grotto. Deep within a natural cavern, the team found a series of magnetite star-maps carved into the floor, aligned with the positions of the Pleiades and Venus as they would have appeared in the Pre-Classic period.
The site also contained a serpentine sacrificial altar and several jade figurines depicting 'sky-gazers' in ritualistic poses. This find suggests that the Olmec possessed a highly sophisticated understanding of celestial movements and used remote cave systems as private observatories for religious and calendrical purposes, cementing their role as the architects of Mesoamerican cosmology.