From its foundation the Roman fort of Eboracum was aligned on a north-east/south-east bearing on the north bank of the River Ouse. It measured 1,600 "pes monetalis" (473.6m) by 1,360 "pes monetalis" (402.56m) and covered an area of . The standard suit of streets running through the castra is assumed, although some evidence exists for the "via praetoria", "via decumana" and "via sagularis". Much of the modern understanding of the Fortress defences has come from extensive excavations undertaken by Leslie Peter Wenham.