Tourists visit Dukezong ancient city of Shangri-la County, southwest China's Yunnan Province, Feb. 1, 2012. Meaning "Moonlight City" in the Tibetan language, Dukezong has been a city in which merchants came to do businesses long ago. Protection work have been intensified in recent years to the ancient city that has a history of more than 1,300 years. [Xinhua/Lin Yiguang]