Enormous, megalithic structures of mysterious origins. A vast underground complex containing the remains of what some believe to be otherworldly beings. Could the ancient mysteries that exist on the Mediterranean islands of Malta be connected to local legends of alien visitation–and giant hybrid beings?

Ancient Aliens is counting down the world's top ten mysterious devices, from strange, grooved disks found in a cave in China to an ancient Greek computer to an incredible crystal skull unearthed in Mexico. Might these sensational artifacts provide evidence of extraterrestrial visitation?