GROUND PLAN OF CONISBOROUGH KEEP.
The entrance to the Keep is only a small square aperture placed in the first floor and approached by a long flight of steps in which at one time a drawbridge occurred. The ground floor contains the well and is entered by means of a trap-door in the vaulted ceiling. The buttresses are excavated in places to form chambers, and in one is situated the oratory described by Scott in Ivanhoe. It is beautifully vaulted in the Early English style, with carved capitals and bases to the supporting shafts. This grand relic of the feudal period was probably built in the reign of Richard I. by Hamelin Plantagenet, the natural brother of King Henry II., who had married into the de Warrenne family, the rich Earls of Surrey.
Another variety of the Cylindrical Keep was that at Orford, in Suffolk, which possessed a cylindrical shaft similar to that at Conisborough, and was supported by three minor towers symmetrically arranged and carried above the battlements. This Keep was protected at the base by a massive wall with a ditch between the wall and the Castle base, and probably suggested the Conisborough Keep and also that at Warkworth, while those at Wallingford, York and Pontefract approximated to the same ideal.