Ancient Aliens

Giorgio Tsoukalos and David Childress explore the mysterious chain of manmade islets in Micronesia's Nan Madol.

In 1947 the U.S. military collected the debris of what they claimed was a crashed weather balloon outside of Roswell, New Mexico.

Chile boasts the highest number of annual UFO sightings of any nation on Earth.

Since the late 1940s, there have been countless reports of mysterious Men in Black that show up immediately following UFO sightings and attempt to silence witnesses.

From Egypt to Easter Island, towering figures built by ancient man stand watch over the Earth.

Shocking new evidence reveals that advanced civilizations might have existed on Earth tens of thousands of years ago.

In numerous ancient cultures throughout the world, stories were told of ancestors that came to Earth from the Pleiades star cluster.

In the Mojave Desert, there is a structure built to bestow everlasting life--and according to the architect, the blueprint was provided by an extraterrestrial visitor.

Accounts of creatures that can shapeshift from one form into another can be found throughout history.

Nestled within a remote valley in Utah, is a ranch that some believe is a hotbed of strange, inexplicable phenomena.

UFO witnesses have reported a wide variety of objects in Earth's skies--and not only in modern times, but for centuries.

The White House has consistently denied having any knowledge of alien craft visiting Earth, but presidential encounters with UFOs and other strange phenomena can be found.