<P> The keep has four floors, including the Great or Banqueting Hall with a central arch extending two stories and a fireplace . The top floor may have been added around the 15th century, replacing an impressive pyramid - shaped roof . This is a recent theory, however, and many older sources have noted the similar plans of Hedingham Castle and Rochester Castle, which was begun about 1126 and has four floors and four turrets . </P> <P> Two of the original four corner turrets are missing, and it seems likely that their demise was a result of an attempt to demolish the building for materials rather than through military action . The keep is the only medieval element of the castle to have survived; the hall, drawbridge, and outbuildings all having been replaced during the Tudor period by structures which--with the exception of a brick bridge--have now also been lost . </P> <P> A chapel was located to the south of the stone keep within the inner bailey . </P> <P> A red - brick bridge of four spans connects the inner bailey to the outer bailey lying to the north - east . It was built in late 15th or early 16th century has been restored several times . A Queen Anne style red - brick mansion was built in the outer bailey by Sir William Ashhurst (an MP and a former Lord Mayor of London) between his purchase of the property in 1693 and his death in 1719 . </P>

When was a square stone keep at hedingham built