The impressive citadel in the Old City of Damascus dates back to the 11th century and is built on the same level as the city, unlike any other fortress in Syria. A Roman military camp first stood on the site before the Seljuks erected the original citadel and fortified the area by building walls, towers, a moat and trenches. With houses, mosques, schools and bath-houses inside, they created a city within a city and made it one of the most impenetrable fortresses in the land. Rectangular in shape and protected by 12 towers, the citadel has all the typical features of Ayybid masonry: large rusticated blocks, massive regular towers and beautiful vaulted interiors.