third Thursday of the month. The BStU has 15 such regional archives in Germany. Artillery Barracks (Artilleriekaserne) The Artillery Barracks was built between 1679 and 1681. Side wings were added to the building in 1825. It was in military use until 1964, when it housed the military headquarters. It was restored 1990–1993. Administrative offices of the Thuringian department for monument protection and archaeology (Thüringische Landesamt für Denkmalpflege und Archäologie, TLDA) are now housed in the building. Maintenance Sergeant's quarters (Schirrmeisterei) The Maintenance Sergeant's quarters was built in 1530 as part of the Monastery of St Peter and Paul. From 1665, when the military took over the site, it was used as the Marketenderei, in English the 'sutler's building'. The sutler was a merchant who accompanied an army in order to sell provisions to soldiers. After 1820 it became a farm yard for the Prussian garrison. St. Leonard's Church (Leonhardskirche) It is not known exactly when the Leonhardskirche was built, but the first mention of it was in 1185. It was originally in the romanesque style, but after the site became a fortress the windows were altered and the building became an artillery store. It was destroyed in a World War II air raid. In the early 1990s the foundations were excavated and can be seen today.<ref name=archilog /> Gallery See also Bastion fort Capitulation of Erfurt Citadel Principality of Erfurt References Buildings and structures in Erfurt Fortresses in Germany Baroque architecture in Germany Heritage sites in Thuringia History of Erfurt Tourist attractions in Thuringia Restored and conserved buildings