The “St. St. Cyril and Methodius” National Library of Bulgaria was establised on 10th December 1878. Today the Library’s collection contains nearly 8.5 million documents. Every year, it receives about 70 000 publications. The National Library “St. St. Cyril and Methodius” is the largest book treasury in Bulgaria. The collections of ‘St. Cyril and Methodius’ National Library: Bulgarian Historical Archive; Official publications; Old, rare and valuable editions; Graphic and cartographic publications; Music editions and sound recordings; Slavonic and foreign language manuscripts; Oriental collections; Specialized Collection in Library Science. The library is a sustainable partner, and there is potential to be involved in a variety of activities: exhibitions, workshops, lectures, competitions considering books heritage.