Barbarastollen underground archive

The Barbarastollen underground archive is an underground archive for preserve Germany’s cultural heritage. The Barbarastollen is in a mine near Freiburg im Breisgau, Baden-Württemberg, Germany. It holds microfilms with about 900 million images from German archives and museums. 
Among the documents stored here are:
The Barbarastollen tunnel is the only cultural property in Germany under the protection of the Hague Convention of UNESCO. It is named after Saint Barbara. The entire complex is buried under 400 meters of rock. It is intended to survive a nuclear war. It is estimated that its contents should survive for at least 500 years without any serious damage.