Returning to the well-stair, the upper part of which is broken away, at twenty-nine steps from the base is a small lancet-headed door. It opens into a mural passage, 2 feet 6 inches broad, and 7 feet high, which makes two turns at right angles. At one, on the left, is a recess, 3 feet deep by 1 foot 9 inches broad, a garderobe, the back part of which, probably bratticed off, carried a shaft from a similar recess on the ramparts. At its second turn the passage descends seven steps to the nearest window recess in the main chamber, crossing which an opposite doorway leads into the mural gallery. The ascent and descent in the narrow passage is rendered necessary by the level of the steps of the well-stair. The mural gallery, at the main chamber level, is continued within the substance of the wall, to the recess next the chapel. It is in plan a polygon parallel with the inner faces of the wall. It is 10 feet high and 3 feet 9 inches wide, having a flagged roof resting on a double tier of corbels, and in it are three large recesses, each opening to the field by a long loop, swallow-tailed at each end. These recesses and loops are not seen from the main chamber. The doors and window frames, where original, are executed in straw-coloured sandstone. The chapel doorway and piscina and the side doors of the window recesses seem of later Decorated work than the rest, and may be insertions, though this does not look probable. The keep, as at Tamworth, Durham, Berkhampstead, Warwick, and Cardiff, stands in the _enceinte_ line of the main ward, and forms part of it, about two thirds of its circumference being outside, and one third, including the doorway, inside the curtain. This curtain was about 460 feet in length, and encircles the main ward, abutting against the keep at two points: one 24 feet south and one 18 feet north of the entrance. On each side it is carried down the slope, and, meeting below, thus encloses a somewhat fan-shaped area, about 170 feet north-east and south-west by 142 feet north-west and south-east, within which were the principal buildings of the fortress. The southern part of this curtain can be traced, but in its foundation only; that to the north is tolerably perfect. It is 7 feet thick, and has been about 25 feet high. It does not, as at Tamworth, so ascend the mound that its ramparts terminate at the level of the base of the keep, but it abuts against the keep at a height of 12 feet or 14 feet, and is so continued down the slope. Up the mound, the rampart of the curtain, as at Windsor, was a flight of steps, but as the ramparts only abutted against, and had no doorway into, the keep, the steps were merely to enable the defenders to man that part of the wall. On the north side, besides these steps, there was a second flight, laid on the surface of the mound, behind and at the foot of the curtain, and probably covered over, as traces remain of a second wall. These led to the entrance to the keep, and were the