Chinese Muslims arrive at the Zhongchuan Airport for their flight to Saudi Arabia in Lanzhou, capital of northwest China's Gansu Province, Sept. 19, 2013. A total of 2,288 Chinese Muslims from Gansu will go on the annual pilgrimage to Mecca on organized trips. The Mecca pilgrimage, also known as the Hajj, is a Muslim religious tradition that specifies that all able-bodied Muslims who can afford to travel to Saudi Arabia must visit Mecca at least once in their lifetime. [Photo: Xinhua]