A monk lights a butter lamp at the Jokhang Temple on the Butter Lamp Day, a festival to commemorates Tsong Khapa, a master of Tibetan Buddhism, in Lhasa, capital of Southwest China's Tibet autonomous region, Dec 5, 2015. The Butter Lamp Day, known as the day of the Ganden Nagchu in Tibet, falls on the 25th of the 10th month of the Tibetan calendar. Tibetan pilgrims adhere to the tradition to light butter lamps and pray for a good fortune on the annual Buddhist event. [Photo/Xinhua]