Ancient Top 10 is smart, fun countdown that details how ancient technology worked, how surprisingly advanced it was, and how it was kind of awesome.

All around the world are examples of physical evidence suggesting humans are not alone in the universe, but has this evidence been left behind for a purpose? Is it a series of clues we are meant to decipher? Giorgio A Tsoukalos investigates.

Ancient Aliens examines 75 million years of the most credible alien evidence here on Earth, from the age of the dinosaurs, to ancient Egypt, to the skies over the western desert in the present day US.