Conspiracy - Did Aliens Build the Pyramids?

All over the world there are giant stone monuments. Almost everyone knows they were created thousands of years ago by ancient man. But could almost everyone be wrong about the pyramids, Aztec Temples, Stonehenge? There are a few nagging questions, like why do they seem to appear out of the blue around the same time? How did the Giza Pyramids attain alignment with true North with an accuracy within 1/10 of a degree? Its a mystery that might be solved if you believe aliens influenced our society by providing the information needed to move and erect these massive stone objects.