LHASA, Nov. 1 (Xinhua) -- The Potala Palace in Southwest China's Tibet Autonomous Region began its annual facelift Friday.

The 1,300-year-old palace, located in Lhasa, capital of the region, has seen 60 workers and hundreds of local volunteers participating in the whitewashing of the exterior of the landmark.

It usually takes about a dozen days to paint the palace, a UNESCO World Heritage Site, in preparation for the forthcoming "Lhabab Duchen," which is believed to be the day the Buddha descended from the heavens and is one of four annual festivals celebrating important events in his life.

The palace said it would open to visitors during the facelift.

The walls of the palace have four different colors: red, yellow, white and black. The red symbolizes authority, yellow prosperity, white peace, and black exorcism.

The Potala Palace was built by Tibetan King Songtsa Gambo in the seventh century and expanded in the 17th century by the Dalai Lama. It received 1.45 million tourists in 2017. The palace was included on the UNESCO World Heritage List in 1994.