Caerleon in Roman times was the base of the Second Augustan Legion and from A.D. 74, with its 'sister fortresses' at Chester and York, formed the main bulwark of military defence in the West.
Today, Caerleon - alone of the three standing - has escaped wholesale destruction by over-building and so ranks archaeologically as the largest and most important Roman military site in Britain.
Recently it became possible to start excavating again and Dr. Nash Williams, of the National Museum of Wales, shows the new discoveries brought to light and discusses them with Sir Mortimer Wheeler.
(A BBC telerecording of the broadcast on November 22)
(to 16.15)