The castellum or castrum of Maastricht [1] was a late Roman fortification or fortress ( Latin : castellum , castrum or castra ) in the center of the Dutch city of Maastricht . The Maastricht castellum was built in or shortly after 333 AD. [2] and probably remained in use until the 9th or 10th century. The fortification was built from heavy wallwork and had ten towers and two gates. Around the fort there was a wide defense moat. The castellum is still recognizable today in the rectangular street pattern of itStokstraatkwartier and the elevated location of the streets.