The 1,300-year-old iconic Potala Palace, located in Tibet's capital Lhasa, has completed a large-scale renovation project on Sunday.

The renovation took nine days and used 92 tons of natural pigments in total.

The project, focused on repairing the palace's gold-plated roof and improving its security surveillance system, was estimated to cost over 10 million yuan (1.5 million U.S. dollars). It was approved by China's State Administration of Cultural Heritage on October 5.

Due to the long-term exposure to wind, sun and rain, parts of the gold plating have been damaged, said Jorden from the palace's administration body, stressing the renovation will prolong the life of the roof.

Originally built in the 7th century, the palace was then rebuilt and extended during the 17th century. It was declared a UNESCO world heritage site in 1994 and is the most famous tourist attraction in Tibet.

Last year, 1.37 million domestic and international tourists visited the place. The number of tourists was restricted to 2,300 per day to avoid overcrowding its narrow rooms and corridors.

According to Xinhua News Agency, the central government has spent nearly three billion yuan protecting cultural heritage in Tibet in the last two decades.