Petra is an archaeological site in Jordan, lying on the eastern flank of the large valley running from the Dead Sea to the Red Sea Gulf of Aqaba. It is renowned for its rock-hewn structures built at the heaight of Nabataen wealth and power (early in the 1st Century BCE). Petra is a UNESCO site and also one of the "New Seven Wonders of the World". Of the top 100 archaeological sites I have visited, Petra places second (after Abu Simbel, Egypt).
The Eastern entrance leads down through a dark, narrow gorge called the Siq ("the shaft"), a natural geological feature formed from a deep split in the sandstone rocks and serving as a waterway flowing into Wadi Musa. Although not as Hollywood popular as The Treasury, The Monastery is Petras largest monument and it is farthest from the Eastern Entrance.
Petra was built as the capital of the wealthy Nabataeans and the centre of the regional caravan trade at the crossroads between the Asian Silk Road, and Trade Routes through Arabia to Africa and Europe. Excavations have demonstrated that it was the ability of the Nabataeans to control the water supply through dams, cisterns and water conduits that led to the rise of the desert city.