Petra survived in the desert partly because its builders solved a water problem most desert cities never fully crack, and it survived in Western awareness only after a Swiss traveller pretended to be someone he was not.
Water in a place that should not have enough
The Nabataeans built an extensive system of channels, cisterns, dams and terracotta pipes to capture, store and distribute seasonal flash flood water and natural springs, engineering sophisticated enough to sustain a large urban population in an otherwise arid environment, a practical achievement that made the settlement viable in the first place, well before the elaborate rock-cut facades most visitors now associate with the site.
Rediscovered by disguise
The site had never actually been lost to the local Bedouin population, but it was unknown to European scholarship until the Swiss explorer Johann Ludwig Burckhardt visited in 1812, travelling in disguise as a Muslim pilgrim in order to gain access to an area otherwise closed to outside visitors, and his published account is generally credited with introducing Petra to Western audiences.
As this entry's companion article covers
The betyls, or god-blocks, carved as abstract representations of Nabataean deities and found behind and alongside the site's more famous Hellenistic and Roman-style classical facades, are addressed directly in this entry's companion article rather than repeated here.