since disappeared, its interior staircase to the upper storey may still be climbed. This second storey would have formed the main chamber in the keep and had a large fireplace and a latrine. Originally the keep would have had a parapet and battlements, since destroyed. Historian Richard Avent considers it "the finest surviving example of a Welsh round tower". The rectangular west tower was a relatively short defensive structure, designed to protect the more vulnerable western slope of the ridge. A similar tower in the south overlooks the entrance to the castle. At the north end of the castle is the hall, stretching across the courtyard; in the east corner is an additional building, probably built by the English at the end of the 13th century. Although the hall is relatively large, 50 by 27 feet (15 by 8 m), these buildings follow a simpler design to those current in England at the time, where a combination of a hall, chamber and a service block in castles was becoming more common. See also Castles in Great Britain and Ireland List of castles in Wales Notes References Bibliography Andrews, Malcolm. (1989) The Search for the Picturesque. Stanford, US: Stanford University Press. . Avent, Richard. (2010) Dolwyddelan Castle, Dolbadarn Castle, Castel y Bere. Cardiff: Cadw. . Brown, R. Allen. (1962) English Castles. London: Batsford. Butler, Lawrence. (2010) "The Castles of the Princes of Gwynedd," in Williams and Kenyon (eds) (2010). Crouch, David. (1992) The Image of Aristocracy in Britain, 1000–1300. London: Routledge. . Emery, Anthony. (2000) Greater Medieval Houses of England and Wales, 1300–1500: East Anglia, Central England, and Wales. Cambridge: Cambridge University Press. . Jones, Alan Ffred. (2010) "King Edward' I's Castles in North Wales – Now and Tomorrow," in Williams and Kenyon (eds) (2010). King, D. J. Cathcart. (1991) The Castle in England and Wales: An Interpretative History. London: Routledge. . Williams, Diane M. and John R. Kenyon. (eds) (2010) The Impact of the Edwardian Castles in Wales. Oxford: Oxbow Books. . External links Cadw visitor information Castle ruins in Wales Castles in Gwynedd Castles of Llywelyn the Great Llanberis Grade I listed buildings in Gwynedd