Situated between the Red Sea and the Dead Sea and inhabited since prehistoric times, the rock-cut capital city of the Nabateans, became during Hellenistic and Roman times a major caravan centre for the incense of Arabia, the silks of China and the spices of India, a crossroads between Arabia, Egypt and Syria-Phoenicia. Petra is half-built, half-carved into the rock, and is surrounded by mountains riddled with passages and gorges. An ingenious water management system allowed extensive settlement of an essentially arid area during the Nabataean, Roman and Byzantine periods. It is one of the world's richest and largest archaeological sites set in a dominating red sandstone landscape. Read more about this site on the UNESCO World Heritage Website.