Entering the court, the curtain on the left, of considerable height, has Norman foundations, 1150, and an Edwardian superstructure, 1350. Outside, a string-course marks the base of the parapet, and the embrasures have a decorated moulding carried all round. The wall extends to the Abbot’s Tower, but upon it is a small rectangular mural tower, called the Avener’s Tower, 1309-15. The Abbot’s Tower, of the same date, caps the north-west angle. It is rectangular and of three stages, the lowest being vaulted and ribbed with segmental arches, as in the Constable’s Tower, and below the Great Hall. The third stage rises clear of the wall, and is reached by a well-stair, which occupies the north-east angle. From this a short curtain of mixed date, 1150 and 1350, with a low salient, extends to the Falconer’s Tower, also rectangular, rebuilt, though not exactly on the old site, in 1856, and from which a modern curtain wall runs up to the Prudhoe Tower of the keep. Upon this wall stood the Armourer’s Tower, also rectangular, destroyed in 1856, to improve the view from the library. The removal of this and the Falconer’s Tower are said to have been the only subtractions made from the original military works of the castle. Returning to the west gate, the curtain on its right extends past the west Garret Tower to the Clock Tower, all rebuilt 1750-86. The latter is circular, with a flat gorge and keel-shaped salient, and caps the south-west angle. Outside the last-named curtain, and reached through it by a gateway, are the stable courts, riding-school, and guest-hall, 135 feet by 35 feet, by 25 feet to the spring of the open timber roof, a very noble structure. These buildings are of modern date, 1856. From the Clock Tower the south curtain supports on its outside the estate offices. Part of this curtain is 1750-86, part 1309-15. This latter part includes the Auditor’s Tower, 1770, of which the square rear projects into the court and the half-round front outside. Beyond this is a bit of Norman curtain, 1150, against which on the outside is built the modern kitchen, and above which a modern corridor communicates between the duke’s room and the record-room in the Auditor’s Tower. The treatment of this part of the structure by Mr. Salvin deserves especial notice from the happy combination of the features of the Edwardian age with the appliances of the present day. The kitchen, with much to remind the visitor of Durham and Avignon, is as a whole superior to either, and is besides a model of culinary arrangement. These offices, originally within the keep at the east end of the hall, were placed here by the first duke, but were recast and rebuilt by Duke Algernon.