South of Amman on the edge of the Wadi Araba desert, Petra is surrounded by towering sandstone hills giving the city some natural protection against invaders. For centuries, this ancient city was the meeting point of the main routes used by camel caravans transporting spices between the Mediterranean and the Near East, Africa, and India. For hundreds of years, Petra was lost to the western world, carved in sandstone and partially buried in sand. Although it dates back to 1200 BC and was built in an area first inhabited nearly 6 millennia earlier, Petra has only been known to the western world since 1812 when it was "discovered" by Swiss explorer Johann Ludwig Burckhardt. Today, Petra is one of the world's most famous and spectacular archaeological sites where ancient Eastern traditions blend with Hellenistic architecture. This symmetrically columned Greek-style building known as the Treasury is hewn from the face of a 130 foot cliff that dates back to 56BC. It is Petra's best-preserved monument since it's sheltered from windblown sand and you might recognize the monument from the 1989 Indiana Jones and the Last Crusade film.