If ancient aliens visited Earth, what was their mission, and is there evidence that points to when they will return? Ancient Sumerian tablets describe an alien race, known as the Anunnaki, who came to Earth to mine for gold.

If ancient aliens visited Earth, who were they, and where did they come from? Possible historic evidence and beliefs are examined around the world.

Mysterious places can be found around the Earth, and, inexplicably, UFOs are often sited near these mystical areas. Planes and ships unaccountably disappear in the infamous Bermuda Triangle.

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

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.

If ancient aliens visited Earth, can evidence of their existence be found in the mysterious structures that still stand throughout the world?

If ancient aliens visited Earth in the remote past, could they have given us advanced technology, past down through human history?

Superhuman strength... Supernatural powers... And the awesome ability to fly. Throughout history, mankind has told incredible tales of gods with extraordinary powers. But are these accounts merely tall tales, or could they be based on factual events?

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?

Ancient Astronaut theorists believe aliens have been visiting earth for thousands of years. If so, might we find evidence of this even in the stories of America's Old West?