About 1,000 years ago, the Dunhuang cave in China was packed with 50,000 paintings and manuscripts, and sealed. In 1900 it was opened, and the contents taken away (stolen?) by western museums and private collectors.
Now over 40,000 documents, from museums all over the world, have been gathered together into an indexed and searchable online collection. And it’s fantastic.
Link: IDP Manuscript Search