Considering the level of bombing sustained by the city in 1942, it is a miracle that so much of medieval Canterbury survives. Among the many attractions are the ruined castle keep and a large part of the city wall. Indeed, though incomplete, the wall of Canterbury ranks among the foremost in England.
The shape of the defenses was determined in the third century AD. The Roman wall enclosed an oval area nearly two miles in circumference, and the medieval wall follows exactly the same line. However, very little Roman masonry survives because the wall was rebuilt from the 1370s, when a French invasion seemed imminent.
More than half the circuit is preserved, extending from the site of the North Gate at the southwest end of the old city. The only gaps in this sector are those left by the demolition of the gatehouses. Eleven bastions survive, notable for their early “keyhole” gun ports. The four northernmost are square and date from about 1400, but the others are the traditional U-shaped type with open backs.
Canterbury Castle was probably founded soon after the Norman Conquest and certainly before the Domesday Book.. All that remains is the lower half of a large, oblong keep. The stepped splays behind the narrow window openings suggest an early date. The plinth and pilaster buttresses are typical Norman features. The entrance was at first-floor level in the northwest wall and excavations have uncovered a fore building.
The West gate is the only survivor of seven gatehouses in the wall. The fortress-like outer façade of the gatehouse, with machicolations overhanging the entrance and sturdy drum towers pierced by gun ports, contrasts with a more domestic townward front. Note the porticullis groove in the vaulted gate passage. The West Gate has survived because it housed the county gaol after the castle keep had become too derelict.