The basement of the gatehouse is at the ground level. On each side of the passage are two chambers, those in front occupying the half-round projection and looped to the field. They are entered from the chambers in the rear, which are rectangular, having shoulder-headed doors from the passage and into the well-stairs. The northern chamber has a fireplace in the south-east angle. The two southern chambers communicate through a large arch, the northern through a doorway only. There are also two upper floors, divided as these below, and reached by the two large well-stairs. There are spacious and handsome rooms, two on each floor, with large windows of two lights in the western or larger rooms, and in all are fireplaces with stone hoods. The eastern rooms below are half circles in plan; and above, are polygonal. Between the lateral rooms and over the entrance passage are two narrow chambers unequally divided by a cross wall. The eastern is an oratory, with a small, pointed east window over the entrance gate of the castle, and near it, in the south wall, is a piscina, which is in the cill of a small window opening into a small mural chamber, a vestry. There is a similar chamber, but without the window, in the north wall. Both rooms are entered from the oratory. As at York, Chepstow, and elsewhere, this oratory served also as a portcullis chamber, and the floor was of wood, with traps to allow the passage of the grates when lifted. The grates were suspended from the vault above, as is still seen. The other and larger chamber, placed over the western part of the passage, had also a wooden floor. It had a west window of two lights over the inner portal, and north of this a round-headed doorway. The portcullis, if lifted, would have blocked this entrance, and therefore when the door was opened it was stopped. The machecoule is seen in the window seat. The upper chambers are not accessible, but they seem similar to those below, and there is a second oratory above the first, with a smaller east window—a very unusual arrangement. This floor communicates laterally with the ramparts of the curtain, and at the junction on each side is a mural garderobe. On the south side a mural stair descends to two chambers at different levels, both in the curtain wall. On the north side the arrangement is rather different. There, the mural garderobes are supported in part by a projection at the first-floor level, corbelled out in the angle between the gatehouse and the curtain, outside, and the vent was probably between the corbels. Above, at the rampart level, half the thickness of the wall is occupied by a garderobe chamber, of which the side is broken down. Several of the chimney shafts are collected in a central group, each shaft having a bold capital with a plain roll moulding.