George Thomas Clark, Mediæval Military Architecture in England…
“ The northern gatehouse, that between the outer and inner wards, is destroyed; but the foundations show a passage 9 feet broad by 33 feet deep, which seems to have traversed a mass of buildings 84 feet broad by 30 feet to 40 feet deep. Of this, the part to the west of the portal, was a nearly rectangular building, 30 feet by 22 feet, having an entrance from the passage, and in its south wall a mural staircase. East of the portal is a much larger building still in part standing, and which seems to have been the keep. ”
