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. But new evidence may prove that the wreckage actually belonged to an extraterrestrial spacecraft.

Chile boasts the highest number of annual UFO sightings of any nation on Earth. Now, incredible new footage of a strange craft has even the Chilean government asking if alien visitors are drawn to this part of the world.

From Egypt to Easter Island, towering figures built by ancient man stand watch over the Earth. Are these stone giants simply a testament to humanity's past or could they depict visitors from another world?

In numerous ancient cultures throughout the world, stories were told of ancestors that came to Earth from the Pleiades star cluster. Could new scientific findings reveal that humankind's true origins lie not on Earth?

Shocking new evidence reveals that advanced civilizations might have existed on Earth tens of thousands of years ago. Is it possible that a technologically advanced society thrived on Earth then?

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

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. Known as the Integratron, it has been called a work of genius.

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 including terrifying creatures, paranormal apparitions and lights in the sky.

UFO witnesses have reported a wide variety of objects in Earth's skies--and not only in modern times, but for centuries. What might we learn from examining their shapes, sizes, and the way they maneuver?

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 going all the way back to George Washington.