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. Will new evidence prove it belonged to an extraterrestrial spacecraft?

Chile boasts the highest number of annual UFO sightings of any nation on Earth. New footage of a strange craft has some asking if alien visitors are drawn to this part of the world.

From Egypt to Easter Island, 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?

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?

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

In the Mojave Desert, there is a structure built to bestow everlasting life. Could the blueprint have been provided by an extraterrestrial visitor?

Accounts of creatures that can shapeshift from one form into another can be found throughout history. Could similarities between the ancient stories and modern-day alien abduction accounts be real?

Nestled within a remote valley in Utah, is a ranch that some believe is a hotbed of strange, inexplicable phenomena. Could the bizarre activity have a connection to an alien entity?

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 them?

The White House has consistently denied having any knowledge of alien craft visiting Earth, but presidential encounters with UFOs are rumored to be found going all the way back to George Washington.