Many ancient cities are thought to be lost forever-if they ever existed at all. See more in this compilation from Ancient Aliens. Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your favorite shows on The HISTORY Channel website at ...

Exploring lost civilizations and hidden knowledge, this documentary dives into the secrets of humanity’s origins. Through speculative archaeology and interviews with experts, the movie examines ancient artifacts, megalithic structures, and the possibility of extraterrestrial influence on early ...

Throughout the ancient world, structures were built to mirror the constellations in the night sky--and, in most cases, this is only apparent when they are viewed from high above the Earth. See more in Season 14, Episode 13, "The Constellation Code." Watch all new episodes of Ancient Aliens, ...

In 1952 cameras spotted UFOs flying over the White House lawn in Washington D.C. - these sightings eventually lead to Project Blue Book, created by the U.S. government, in this clip from Season 5, "Aliens and Cover-Ups." Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to ...

Are these ancient stone structures actually harnessing energy from our planet? See more in this compilation from Ancient Aliens. Watch all new episodes of Ancient Aliens, Fridays at 9/8c, and stay up to date on all of your favorite shows on The HISTORY Channel website at ...

Check out these top 3 alien cover-ups, in this Ancient Aliens compilation. Chapter 1 - 0:00 - Southwest English County Haunted by UFO Chapter 2 - 05:37 - Mystery of the Roswell Crash Looms Large Chapter 3 - 09:17 - Blinding Lights Obstruct Montana Military Base Watch all new episodes of ...