The ancient city of Petra is one of Jordan's national treasures and by far its best known tourist attraction. Located approximately three hours south of Amman, Petra is the legacy of the Nabataeans, an industrious Arab people who settled in southern Jordan more than 2,000 years ago. Admired then for its refined culture, massive architecture and ingenious complex of dams and water channels, Petra is now a UNESCO World Heritage Site that enchants visitors from all corners of the globe. Much of Petra's appeal comes from its spectacular setting deep inside a narrow desert gorge. The site is accessed by walking through a kilometre long chasm (or Siq), the walls of which soar 200m upwards..