More to explore:
Pevensey - William the Conqueror's First English Castle - and St Mary's Church (4)
by antonychammond on Flickr (cc)
William the Conqueror | William the Conqueror Photos & Images - Download Free William the ...
William The Conqueror (Documentary)
Barclay Towie Castle - not sure if this is what the original castle looked like, but it did come up in a search.
William the Conqueror - Part 3
William the conqueror week 2
Dried stone wall above the Ladybower Reservoir in Derbyshire, England
Tomb of William the Conqueror (Guillaume le Conquérant) - Abbaye aux Hommes, Caen, Normandy, France
Totnes, Devon, England (by Fragga on Flickr)