Photo taken on Sept. 5, 2014 shows prayer flags set up by Tibetan Buddhism believers living in the Zhagana region in Diebu County of Gannan Tibetan Autonomous Prefecture in northwest China's Gansu Province. Zhagana is a mountainous region on the northeastern rim of the Tibetan Plateau, with an average altitude of 3,500 meters. The region has a unique cultural and natural landscape featuring Tibetan-style villages, primitive forests and mountains formed during the quatenary glaciation. (Xinhua/Zhang Meng)