Ancient Aliens

Some of the Earth's most remote caves were once inhabited by our oldest forebears. Experts examine the theory that they might also reveal alien contact.

It's one of the world's most famous structures, but how much do we really know about the Great Sphinx of Giza? Researchers speculate on its origins.

Ancient astronaut theorists discuss the interconnectedness and technological savvy of the modern world. Is it too brilliant to be purely human-built?

At key moments in human history, great thinkers have found astonishing ways to advance mankind. Is it possible to explain the origins of their genius?

From gifts for the gods to elaborate costumes, investigators look at our historic approach to the afterlife and search for otherworldly explanations.

Stories of the afterlife and resurrections have ignited our interest throughout history. Researchers suspect extraterrestrial forces may play a part.

Theorists examine sacred texts and ancient monuments for the secrets hidden within and ask what role aliens might have played in their mystique.

Investigators look at tales of great floods sent by the gods, and wonder if these mythical deluges have an otherworldly connection.

Did aliens steer the outcome of the American Civil War? Researchers unpick the history books for evidence of paranormal forces.

As infrared technology detects long-lost pyramids buried deep beneath the ground, theorists consider what more we have to discover on Earth.