"The physical evidence proved the central government's rule in the region then," said Yan Yilin, director of the archaeology department of the National Cultural Heritage Administration.

Wang Wei, president of the Archaeological Society of China, said the Tang sites are also highly inspirational for studies of cross-border cultural exchanges along the Silk Road.

Last year, which marked the centennial of the birth of modern Chinese archaeology, more than 1,700 archaeological projects were conducted nationwide, the most in history.