Tourists who want to visit the Mogao Grottoes in northwest China's Gansu Province without a reservation will find them hard to enter since a booking system for the grottoes was launched Tuesday.

Liu Huilin, deputy director of the China Dunhuang Studies Institute, said that the system aims to relieve the pressure of the peak tourism season.

Researchers have found that besides sand, wind, rain and insects, touching and condensed breathing of visitors are also the causes for the deteriorating grotto murals.

From 2000, the Dunhuang Studies Institute divided its 50 already opened grottoes into eight visiting routes for tourists, but this effort did not curb the pressure from the high tourism season, when over 3,000 tourists are received daily.

Liu suggested that Chinese and overseas travel agencies apply for reservations from the Dunhuang Tourism Bureau, or else his institute will reject their tourists.

The grottoes hold 45,000 square meters of murals and 2,000 figurines that were made from the fourth to 14th centuries. They have been added to UNESCO's world cultural heritage list and have attracted thousands of visitors from around the world.

(Xinhua News Agency April 2, 2003)