[Photo by Wang Kaihao/China Daily]

"The frescoes in the Drepung Temple are key to studying the development of Tibetan Buddhist art," says Guo Hong, a researcher from the academy, who has led the restoration work since 2012.

"They offer abundant material to study Tibetan history and society."

Speaking of the restoration process, Ngakwang Chozen, a high-ranking lama and deputy head of the administration committee of the monastery, says: "We were undecided on repairing the frescoes at first. But these frescoes with Buddhist deities have a special place in pilgrims' hearts.

"And, if they are not in a good condition, people would be sad. So, we felt it was better to make them look bright again."

After studying other restoration work done by the academy, Ngakwang Chozen gave his approval for the work at the monastery and performed a blessing ceremony for the project, which covers 966 square meters of frescoes.