The Dungeon - This room at the base of the Norman Tower was almost certainly a cellar. As it has neither a fireplace nor a window, it may have been used to detain prisoners in the medieval period, there are references to prisoners at Tamworth Castle in orders written by King John in 1215. Its front wall is 14 feet (4.3 m) thick, it is 18 feet (5.5 m) high and 13 feet (4 m) square inside.