Mamucium, also known as Mancunium, is a former Roman fort in the Castlefield area of Manchester in North West England. The castrum, which was founded c. AD 79 within the province of Roman Britain, was garrisoned by a cohort of Roman auxiliaries near two major Roman roads running through the area. Several sizeable civilian settlements containing soldiers' families, merchants and industry developed outside the fort. The area is a protected Scheduled Ancient Monument.