Berwick Ramparts are a huge complex of 16th century town fortifications, founded by Queen Mary. Built inside the medieval town wall, which was then abandoned, they gave defence against the development of artillery and are unique in Britain. One and a half miles in length, the stone-faced ramparts are strengthened by immense arrowhead-shape bastions, which flanked huge wet ditches. The open ground of Magdalen Fields, is protected by the Bell Tower and an earthwork traverse line, which ends with the Great Bulwark Redoubt. Cowport is the only Elizabethan gateway remaining, its vaulted tunnel through the rampart was defended by a portcullis and still has a massive 18th century wooden gate. In the 17th century, the ramparts were given an earthwork parapet and all the bastions except King's, were heighten with earthwork cavaliers. Nearby is the Lord's Mount and Berwick Castle.