Since opening to the public in 1979, the number of tourist visits surged from 26,000 to a peak of 2.2 million in 2019. Last year, with visitation reduced by the coronavirus, it welcomed 1.39 million visits. Now, it has about 20,000 foreign visits annually, mainly from Japan, the United States and South Korea.

The attraction offers guided services in six languages－Chinese,English, Japanese, French, Korean and German. All films, exhibitions and signboards have English translations.

In addition to sightseeing, tourists can view the restoration process, digital information collection, environment monitoring center and documents excavated from the caves, Li said.

Because the pandemic curbs travel, the grottoes have developed digital platforms, such as online museums, WeChat mini programs and livestreaming for whoever has an interest. The academy has also published a series of academic books for primary and middle school students.

Immersive, interactive digital experiences are offered elsewhere in the city. Yangguan Pass, for example, invited tourists to experience the grand ceremony of sending off envoys and soldiers in ancient times, including the issuance of customs clearance documents, a farewell drink of alcohol and the gift of a willow branch. Giving willow branches was a tradition to say farewell to friends in ancient China.

Tourists can also shoot arrows, ignite signal fires, make rubbings, copy wall paintings and color pottery in classes－all ways to meet the growing demand for in-depth, hands-on experiences, said Wu Fengping, deputy general manager of the scenic spot.

Located 70 km south of urban Dunhuang is Yangguan Pass, known by most Chinese from a poem by Wang Wei of the Tang Dynasty (618-907).

"I invite you to drink a cup of wine again. West of the pass no more friends will be seen," Wang wrote.