'Ruins of the Barbican on Ludgate Hill, 1792, (1897). Remains of a Roman watch tower in the City of London. A barbican was a fortified outpost or gateway, and the area of the City now known as Barbican got its name from the main fort of Roman London which was built between 90 and 120 AD. The Roman town of Londinium was surrounded by walls on three sides, with the River Thames as the southern defence. From Old and New London, Volume I, by Walter Thornbury. [Cassell and Company, Limited, London, Paris & Melbourne, 1897]