The story of the poisoning of Sir Thomas Overbury is also told and the lower chamber is furnished as it might have appeared during Sir Walter Ralegh’s imprisonment.

Built in the early 1220s to control the main river entrance to the castle, after 1280 the construction of the outer defensive wall left this tower land locked.  It then became the principal access from the inner to the outer ward with the lower chamber containing superior lodgings.  The upper chamber was largely rebuilt during the reign of Edward III.