The ancient Nabatean city of Petra lies in the barren desert of southern Jordan. Its ruins, spread across an area of over one square mile, include temples, a great theatre and hundreds of tombs built into the desert's rocky cliffs. Today, Petra attracts tourists in their thousands. But it also holds a mystery that has long puzzled historians. What could have led such a grand and elaborate city to be abandoned? After studying the latest evidence, Dr Tom Paradise proposes a new theory about its demise.

Archaeologists explore the remains of ancient Babylon in attempt to uncover the truth behind the Biblical story of the Tower, a construction high enough to reach Heaven until God struck it down.