Magnis or Magna was a Roman fort on Hadrian's Wall in northern Britain. Its ruins are now known as Carvoran Roman Fort and are located near Carvoran, Northumberland, in northern England. It is thought to have been sited with reference to the Stanegate Roman road, before the building of Hadrian's Wall, to which it is not physically attached. In fact the Vallum ditch unusually goes north of the fort, separating it from the Wall. The fort is now the site of the Roman Army Museum.