Ancient Astronaut Theorists believe that Prince William might've investigated and researched a classified UFO phenomenon, in this clip from Season 18, "The World on Alert." Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your favorite The HISTORY ...

Ancient Astronaut Theorists believe that the colossal tower of Jupiter was erected by ancient sky gods, in this clip from Season 18, "Beneath the Sacred Temples." Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your favorite The HISTORY Channel shows at ...

Former police detective Dave Paulides investigates a mysterious disappearance at Mount Shasta, in this clip from Season 17, "The Mystery of Mount Shasta." #AncientAliens Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your favorite The HISTORY Channel ...