The North-West Corner.
The arrangements of the rooms in the North-West Corner is now somewhat confused.
Look for the joist holes in the walls on the ground floor. There is a possibility that a partition ran across the room here, near to the entrance to the double garderobe. This room would have been slightly longer than the Retainers' Kitchen and, again, heated by borrowed heat from the back of the fireplace in the Retainers' Kitchen. Access would have been through a doorway from the courtyard.
Between the corner of the courtyard and the North-West Tower was another room with a double garderobe built into the thickness of the curtain wall. It is likely that there was a partition dividing this room from the ground floor and was entered from the courtyard, again with no windows or fireplace. This room, very bare and cold, must have been some sort of service room, perhaps a stabling. However, this room being a stable is still not confirmed since, although there must have been some sort of provision for horses within the castle, there have been no internal drains, or other features usually associated with stabling, found near the room.
The North-West Tower is entered from the ground floor. Each of the three chambers contains a garderobe and fireplace and each well lit by lancet windows. From the upper chambers there is access to the curtain wall and then to the Gatehouse. In the ground floor there must have been a trap door leading down into a deep basement 12 ft 6inches below the tower. It is believed that this was the main dungeon of the castle.