In a cliff near Dunhuang on the Silk Road in north west China there are hundreds of caves cut and painted over a millennium by Buddhist believers.
Early last century thousands of scrolls, pictures and artefacts were taken from this great gallery in the desert and are scattered in museums and collections all over the world.Now they are being reunited - on the internet.
Isabel Hilton visits the caves, Beijing and the British Library and tells a story of international co-operation and digital technology that is leading to the creation of a virtual Dunhuang.
A virtual Dunhuang will be accessible to everyone, but it may make it more difficult to visit the site physically.
She does go to the caves, to the National Library in Beijing and to the British Library, investigating the implications for the conservation of this great art gallery in the desert, and the vexed question of the return of artefacts.