Enormous manmade caves... Unexplainable structures... And underwater discoveries that challenge everything we know about the past...Is it possible that an advanced civilization inhabited Earth thousands of years ago? And if so, were they human, or something out of this world? Modern archaeologists are continuously unearthing artifacts and sites that defy the conventional timeline of human history. See more in Season 10, Episode 1, "Aliens B.C."

#AncientAliens

Subscribe for more from Ancient Aliens and other great shows:
https://aetv.us/subscribe_unxplainedzone

From mysterious and supernatural occurrences, to extraordinary stories and investigations of the unknown, The UnXplained Zone is your portal to the paranormal. Follow the evidence, uncover the coverups, and discover what lies behind mankind's greatest mysteries and the world's strangest phenomenons.

Welcome to the UnXplained Zone.