Work to set up a database to help better protect the ruins of an ancient Tibetan kingdom dating back to the 10th century in Southwest China's Tibet Autonomous Region, has begun and is proceeding well, according to local cultural authorities.

As a crucial part of scheme, murals of the kingdom and of its temples in nearby areas, totalling 4,000 square metres, will be copied.

These will be used as reference for future restoration as the original relics are susceptible to natural adversities, said Namga Doje, head of the cultural bureau of Ngari Prefecture.

Three painters are currently copying murals at the castle ruins of the Guge Kingdom, located in Zhada County, Ngari Prefecture in western Tibet.

Panoramic photography and architectural measuring of the castle ruins of the kingdom will also be carried and will be compiled into three-dimensional materials, for both future restoration reference and cultural exchanges around the world, Namga Doje noted.

He said the database for the Guge Kingdom, which will be the first for a historical site in Tibet, is expected to be completed in three years.

The Guge Kingdom spanned about 700 years before disappearing mysteriously in the 17th century.

The castle ruins of the kingdom lie at a hilltop near a river, covering 180,000 square metres.

The three-story structure includes more than 300 houses and cave dwellings, with palaces on the top floor, monasteries in the middle and cave dwellings for serfs at the bottom.

The castle was built with solid fortifications. Part of it remains in good shape in this seldom trodden region.

The ruins are famous for murals of more than 1,000 square metres, sculpture and stone inscriptions, which depict mainly stories of Buddha, Sakyamuni and kings of Guge and their ministers.

The ruins of the Guge Kingdom were listed as one of the major national cultural protection units in 1961. China is bracing for filing an application to add the ruins to the World Cultural and Natural Heritage List of the United Nations Educational, Scientific and Cultural Organization.