– Xochielt Sanchez
Answer by Jon Mixon:
It was “lost” in the sense that it was unknown to Western world until 1812. It was known to the inhabitants of the area, it was frequently looted and it was visited often by the rulers of the area until modern times.
Petra, like Machu Picchu in Peru and Ankgor Wat in Cambodia and Anasazi cliff dwellings in what is now Southern Colorado were never “lost.” They were simply unknown to the Western colonial powers which conquered the areas where they were located. Their presence was well-known to locals who chose to stay away from them for reasons of custom, safety and practicality.