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.
Carisbrooke Castle is an extensive fortress situated on a hill about a mile southwest of Newport, virtually in the center of the Isle of Wight. As a fortification, it has a very long history, because the Norman castle is raised on the site of a Roman fort and is surrounded in turn by Elizabethan defenses designed to withstand artillery.
The Elizabethan rampart surrounds the two baileys of the Norman castle in concentric fashion. This low, artillery-proof earthwork is encased in stone. There are arrowhead bastions at the corners and a fifth one on the west, commanding the entrance. Beyond the simple gateway through the rampart, one is confronted with the main gatehouse. It began as a thirteenth century gate tower but in 1336, at the start of the Hundred Years War, Edward III extended it outwards.
Round turrets flank the handsome façade and there is a row of machicolations above the entrance. The long gate passage, with three portcullis grooves, leads into a western bailey, which occupies the site of the Roman fort. Instead of utilizing the Roman wall, the Normans raised a massive rampart over it and piled up a lofty motte in one corner. Nevertheless, the Roman masonry still peeks out from the bank in several places.
Before long, a polygonal shell keep was placed on the motte and a new wall was built on top of the bailey rampart. The rampart is so powerful that the curtain only needs to be of modest height.
During the Elizabethan modifications, artillery bastions were added at the south corners of the curtains, but encased within both are square, open-backed towers. Clearly, they are early examples of mural towers and they are too small and too widely spaced to be effective as flankers. They support the written evidence that the curtain was built by Baldwin de Redvers.