 Complete the following phrase:  The monasteries and churches from the 14th century represent the Serbian Orthodox legacy. Architectural heritage from the Ottoman period includes mosques and hamams from the 15th, 16th and 17th centuries. Other historical architectural structures of interest include kullas from the 18th and 19th centuries as well as a number of bridges, urban centers and fortresses. While some vernacular buildings are not considered important in their own right, taken together they are of considerable interest. During the 