The National History Museum, located in Boyana, it has a vast collection of more than 650,000 historical items dating from Prehistory to the modern era, although only 10,000 of them are permanently displayed due to the lack of space. Smaller collections of historical items are displayed in the National Archaeological Museum, a former mosque located between the edifices of the National Bank and the Presidency. Two natural sciences museums—the Natural History Museum and Earth and Man—display minerals, animal species (alive and taxidermic) and rare materials. The Ethnographic Museum and the Museum of Military History hold large collections of Bulgarian folk costumes and armaments, respectively. The Polytechnical Museum has more than 1,000 technological items on display. The SS. Cyril and Methodius National Library, the foremost information repository in the country, holds some 1,800,000 books and more than 7,000,000 documents, manuscripts, maps and other items. 