I found the last line of this article very interesting:
Archaeologists are still trying to unravel the history of the Nabataeans, which in large remains unknown. Just how they managed to make the rapid conversion from a Nomadic tribe to the builders of great cities is mind-blowing, and has led some to doubt whether they were in fact the original creators of these great cities and monuments.
Possibly the Nabeteans had help from some more intelligent influence? Ala Ancient Aliens… otherworldly batman!