Ancient Astronaut Theorists reveal the original origins of the Aztec's. See more in this clip from "Aliens and Unexplained Engineering." Watch all new episodes of Ancient Aliens, Friday, January 6th, at 9/8c, and next day on The HISTORY Channel website at http://history.com/schedule. ...

Ancient Astronaut Theorists believe a massive pyramid located in Teotihuacan, Mexico could commemorate the arrival of extraterrestrials, in this clip from Season 18, "Decoding the Dragon Gods." Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your ...