Henry Carter Hull

Giorgio Tsoukalos takes a look back at the most extraordinary encounters that, as far as he's concerned, provide evidence of an extraterrestrial presence on Earth.

Biblical texts and ancient lore frequently describe winged creatures carrying messages from the heavens. But are angels merely the product of mankind's imagination--or do they really exist? If so, where do they come from? Ancient astronaut theorists suggest that the Bible's Old Testament reads like a handbook on extraterrestrial visitations.

What is the meaning behind secret messages found throughout Washington, D.C.? Did America's Founding Fathers know something about ancient aliens that the general public did not? And if so, could this knowledge have been incorporated into the symbols?

Unearthly visitations... Heavenly messengers... Close encounters... Accounts of humans interacting with celestial beings have existed since the beginning of mankind.

Mysterious legends and crumbling ruins are all that is left of our planet's lost worlds. But could there be proof of ancient alien visitors hidden among the artifacts of civilizations that have long vanished?

Across the globe, high-ranking government officials are openly talking about Unidentified Aerial Phenomena. Ancient Astronaut theorists suggest the evidence has become too great to ignore.

Ancient underwater cities can be found around the globe, but could these aquatic worlds be the ruins of unknown civilizations--or even proof of extraterrestrial visitations?

Why are humans so different from every other species on Earth? Did we evolve from ape--or is our intelligence the result of contact with an otherworldly source? Could unexplained advances in human evolution be the work of interstellar beings?

In the 20th century, a mysterious British woman who claimed to be the reincarnation of an ancient Egyptian priestess shocked Egyptologists by accurately locating countless structures and artifacts in the Nile Valley. Could it be true?

Ancient Aliens has traveled to many mysterious sites that seem to defy explanation. Now, Giorgio Tsoukalos takes a look back at some of the most incredible structures we've visited all over the world.