How can an entire mountainside become a massive building? The nearly 150 feet high Caverns of Petra became immense temples but who were the people who carved these astonishing monuments and how could they have carved them out of solid rock? The decision to build in that particular area has mystified scholars and historians for centuries because there was no natural source of water supply and the locale was far from hospitable. This Petra documentary answers these and many more questions about this incredible place.