Since the start-up of Uppsala University Library in 1621, large amounts of material have arrived through purchases, donations and compulsory deliveries - printed material that must be saved according to law.
All publications are today distributed among the library's eleven buildings.
The library is and has long been a valuable asset.
Partly for students who use the premises daily, and partly for researchers who can request material from the large collection if necessary.
Change in progress
In the heart of Carolina Rediviva, there are rooms with materials to which the public does not have access.
Several hundred-year-old material from the valuable collection is stored there.
And with 400 years on its neck, the library is on the road to change.
Watch the clip to follow into the secret room.