This photo taken on June 2, 2013 shows the ruins of Avdat in the Negev Desert, south Israel. The World Heritage Committee recorded the Incense Route-Desert Cities in the Negev on the United Nations Educational, Scientific and Cultural Organization's World Heritage list in 2005. The official citation reads: "The four Nabatean towns of Haluza, Mamshit, Avdat and Shivta, along with associated fortresses and agricultural landscapes in the Negev Desert, are spread along routes linking them to the Mediterranean end of the incense and spice route. Together they reflect the hugely profitable trade in frankincense and myrrh from south Arabia to the Mediterranean, which flourished from the 3rd century BC until the 2nd century AD. With the vestiges of their sophisticated irrigation systems, urban constructions, forts and caravanserai, they bear witness to the way in which the harsh desert was settled for trade and agriculture." (Xinhua/Yin Dongxun)