It is one of the most spectacular entrances unimagined. The thirty minutes it takes to travel the Siq, the narrow gorge with walls over 100 meters high on the access Petra, are a time for longing for the longing to reach the end, at that crack in the rock through which an image is seen a thousand times and a thousand times imagined view: the Treasury of Petra, the Al-Khazneh, the impressive Nabatean tomb greets visitors. The Treasury, like all Petra, is a daunting engineering work for more than 20 centuries. The ancient city of the Nabateans is carved into the rock, mountains emptied to build inside tombs or temples. A place with the magic of these sites disappeared for centuries, known only to its nearest neighbors, and fortunately rediscovered by adventurers to whom we owe so much.