Workers paint the exterior wall of the Potala Palace in Tibet autonomous region. The renovation project over the building will be finished before Nov 3 this year, which is September 22 on the lunar calendar of the Tibetans. Tibetan Buddhism considers Sept 22 on Tibetan calendar as the day on which Buddha Sakyamuni returns to the earth from heaven, thus it is called "Buddha's Return Day" or "Sakyamuni's Return Day". [Photo/Ecns.cn]