The Royal Library in Copenhagen, Denmark (Danish: Det Kongelige Bibliotek), is the national library of Denmark and the university library of the University of Copenhagen. It is the largest library in the Nordic countries.
It contains numerous historical treasures; all works that have been printed in Denmark since the 17th century are deposited there. Thanks to extensive donations in the past the library holds nearly all known Danish printed works back to the first Danish book, printed in 1482.
The English version of the website is 
More information on the Wikipedia page