Among the Roman relics in Canterbury are the remains of the town walls. Canterbury was surrounded by a wall in Roman times. It was not until a period of unrest across the Empire in the 270's that a ditch and wall around the city was constructed. The route that the Roman engineers chose is the one followed by the remains of the walls today. The walls were substantially rebuilt in the late-1300's, but Roman traces survive in three places (St Mary Northgate Church, Queningate, and in the Castle grounds).
This is a photo of part of the city walls of which 3 quarters still remain today, they are built purely of flint and look very impressive guarding the cathederal and the city center
Canterbury's city walls are remarkably well preserved and extend a long way round the old centre. You are able to walk along them as well.
This part of the wall includes Queningate.
Some of the original city walls are still here, best seen walking along the pathway in the Dane John Gardens.