In this episode of "Mysteries of UFOs," we explore the controversial theory of Ancient Aliens, which suggests that extraterrestrial beings visited Earth in ancient times and influenced human civilizations. Evidence includes enigmatic structures like the Pyramids of Giza and Teotihuacan, mysterious geoglyphs like the Nazca Lines, and ancient texts describing advanced technology. The theory challenges conventional historical narratives, sparking debate between proponents and skeptics about the role of extraterrestrial influence in shaping human history.