National archeological museum is housed in Buyuk Dzhamiya (The Large Mosque) – the oldest preserved building in Sofia from the age of the Ottoman Dominion, dating back to the end of the 15th century.National archeological museum expositions are placed on two floors. Finds from the Late Bronze Age to the Late Middle Ages are presented in the main hall of the Archaeological Museum.
A large part of the exponents are related to the flourishing of Thrace in the 5th – 3rd century BC and the Odrysian Kingdom. Finds of the mound necropolises of the Thracians are also presented.
On both sides of the entrance of the main hall visitors can see tombstones, statues of idols, ceramics and other articles, which were found along the shores of Black and Aegean Sea. Very well preserved Roman stone monuments – portrait statues, works of Greek sculptures are also kept here.One of the richest collections of Bulgarian Middle Age paintings are placed on the second floor where the Middle Age hall is located. The most valuable exponents of the National archeological museum – the Valchitran Treasure, dating back to the 14th – 12th century BC, and the Lukovit treasure dating back to the 4th century BC are stored in the Treasury Hall on the second floor. The finds made in the Svetitsa Mould by Kazanlak are also stored here.They contain the famous burial mask, as well as the head of the bronze statue of the Golyama Kosmatka mound by the town of Shipka.