Sand is implacable here in far western China. It blows and shifts and eats away at everything, erasing boundaries, scouring graves, leaving farmers in despair. It’s one of many threats to the major tourist draw of Dunhuang, a city on the lip of the Gobi desert: the hundreds of rock-cut Buddhist grottoes that pepper a cliff face outside town.

Known as Mogaoku – ”peerless caves” – and filled with paradisiacal frescos and hand-molded clay sculptures of savior-gods and saints, they are like nothing else in the Chinese Buddhist world. And Mogaoku is in trouble. After a dramatic increase in traffic, the caves are deteriorating because of high levels of carbon dioxide and humidity.

A detail of a scene with flying apsaras, a type of celestial chorine. (The umbrella in the left-hand corner shelters Buddha.)Set between Mongolia and Tibet, Dunhuang was a vital juncture on the Silk Road. Because of its gateway position, it was where Buddhism spilled out of India and Central Asia into China, leaving a residue of spectacular art.

An array of painted sculptures.The earliest examples of caves, small and plain, were used for shelter and meditation, occasionally for burials. By the early fifth century, however, larger grottoes were excavated as temples and monastic lecture halls. Many had chapel-like niches and freestanding altars, all cut from stone. The interiors were sculpted with architectural features as if to simulate buildings.

A hunting scene, painted in a cave in Dunhuang.Painting covered everything. Murals illustrating tales from the Buddha’s past lives, were popular, as were images of court fetes. Rock ceilings were covered with fields of decorative patterning to evoke an illusion of fabric pavilions. Any leftover space was filled with figures of tiny deities.

A fifth-century painted Buddha, sprinkled with desert dust, shows some deterioration. Sculptures for the most part were made of mud. But the body of the 75-foot-tall Buddha in the cave known as “Nine-Storyed Temple” is carved from the rock face and plastered over. His feet are planted at the cliff base; he looks out through a window carved at the top.

An illustration of buildings from the Infinite Life Sutra. By the 11th century Dunhuang’s fortunes were in decline. Sea trade had cut into Silk Road traffic. Regional wars left the town isolated and forgotten. Nature went to work. Sand from the dunes swept into the grottoes. Rock facades gave way, leaving interiors exposed. When people finally reappeared, the damage only increased.

An illustration of Mount Wutai, located in the Creating Harmony Temple in Wutai County.Plans are therefore under way to recast the entire Dunhuang experience in a way that will both intensify and distance it. Digital technology will give visitors a kind of total immersion encounter with the caves impossible before now, but that immersion will take place 15 miles from the site. The question of access versus preservation is a poignant one and is by no means confined to Mogaoku. What are we willing to give up to keep fragile monuments intact?

Photo: Wu Jian/Dunhuang Academy