The library used to be the part of the monastery grammar school. The biggest handwritten book of the world - Codex Gigas, or so-called the Devil’s Bible was placed here for almost 200 years - during the fifteenth and sixteenth century. Today the library can be seen on a guided tour. Beautiful historical interiors hold only 17.000 volumes, a mere fraction of the original collection. Many of the books were destroyed over time. The worst destruction took place under the Communist regime.