Photo taken on July 9, 2009, shows the Potala Palace is illuminated in Lhasa, capital of southwest China's Tibet Autonomous Region at night. (Xinhua/Yang Guang)

The Potala Palace, listed as a world cultural heritage site, is a major religious and tourist site built in the seventh century. The number of tourists has been steadily increasing since July this year, after the impact of the March riot last year badly hurting the local tourism.