The third portion of the curtain also runs along the river cliff, and extends 90 feet from the north-east drum tower to the north gatehouse, near which it makes a salient angle. Between this angle and the gate it is 5 feet thick; elsewhere, only 2 feet. Possibly there was a tower at the angle. The mural towers are three in number, all placed in the western curtain. They are half round, 30 feet high, 22 feet in diameter, with an external projection of 8 feet, and a slight square projection within formed by the gorge wall. They have a ground floor, looped, a first floor with a fireplace, and a chamber on the level of the rampart walk and forming a part of it. The walls are 5 feet thick. The middle tower of the three has fallen into the fosse. The masonry of these towers is rude, and they are ill-bonded into the wall. The offices in this ward are represented by the walls of a detached building, 65 feet by 30 feet, with high gables, placed west of the inner ward; another room, 60 feet by 35 feet, built against the river curtain, near the northern gatehouse; and some outbuildings, kitchens probably, and a bakehouse, built against the curved curtain, close west of the same gatehouse. These buildings were probably intended for the accommodation of the garrison. The main ditch sweeps round the north, west, and south sides of the outer ward, opening upon the river cliff at, and rising towards each end. The opening at the south-east end, near the great gatehouse, is closed by a _batardeau_, which seems to have been embattled towards the river, and to have been approached from the barbican. There are some traces of a similar wall at the other end, next the north gatehouse. This ditch is high above the river, but is fed by land waters, and part of it is still wet. It is about 30 feet broad, and of considerable depth. Westward it gives off a branch which divides the north and south outworks, and communicates with the ditches of the former. The barbican appears, from the traces of its foundations, to have been a small, circular tower. It occupied a rocky knoll on the counterscarp of the main ditch, opposite the great gateway, and on the edge of the steep bank of the river. It evidently was intended to cover the drawbridge, and to force those who arrived by this entrance to pass exposed to the fire of the adjacent western curtain. This work seems to have been cut off from the other outworks by a dry ditch, or covered way, leading from the river, south-west of the barbican towards the main ditch. The outworks are divided into north and south platforms by the branch of the main ditch already mentioned.