At an ancient pyramid complex in Mexico dating back to the first century AD, archaeologists explore hidden tunnels beneath the temple—uncovering mysterious chambers where strange gold spheres raise provocative questions about advanced knowledge or otherworldly influence. #AncientAliens | Ancient Aliens: Out of This World Moments

A stunning find in a tunnel underneath the ancient city of Teotihuacan, Mexico, connects the Aztec calendar with the mysteries of the cosmos. | Ancient Aliens

In New Mexico, researchers revisit the earliest days of exploration and uncover evidence that a devastating weapon—disease—may have spread through indigenous populations with unnatural speed, possibly altering history itself. #AncientAliens | Ancient Aliens: Out of This World Moments