The east chamber, 50 feet by 20 feet, has in its north end a deep recess, and a loop up to which the sill is stepped, while the arch overhead rises as the recess contracts. It is evident that the recess at the south end was similar, but has been converted into a doorway. This is the opening in general use, from the first landing of the exterior staircase. The wall here is 24 feet thick, and there are rebates for two doors, with bars within each. The arches are segmental and the angles rounded off. The alteration seems to have been made in the Decorated period, with a trace of later work. Close east of this door, and 6 feet below it, is another door, now partially concealed, which led into a vault 28 feet by 15 feet, occupying the south-east angle of the building. In its south wall a door leads into a second vault, 23 feet by 15 feet, below the lower vestibule and chapel. Each vault had a loop towards the east. They are now used as water-tanks, and reached by external openings. Returning to the east chamber, in its east wall are two doors, one at its north end and one near the middle, now blocked up. The northern door opens into the lobby of the north-east staircase, and from it a door led into a vault 28 feet by 12 feet, in the forebuilding, now used as a magazine, and entered through the outer wall. The middle door probably led into another vault, of which nothing is known. Thus at the ground level of the forebuilding there are three, if not four vaults, all originally entered from the keep. They are about 6 feet high to the arch-springing. The west chamber, 50 feet by 16 feet, has a large recess and loop in each end, and in the west wall two doors, one opening into the lobby of the south-western staircase, where is the modern door, and the other, now blocked up, which led into a mural chamber 39 feet long by 12 feet broad, now a powder-magazine, and entered from the outside. The first floor also contains two main rooms which communicate by a small door near the north end of the cross-wall.