 The ground floor of the State Apartments retains various famous medieval features . The 14th @-@ century Great Undercroft still survives , some 193 feet ( 59 m ) long by 31 feet ( 9 @.@ 4 m ) wide , divided into 13 bays . At the time of the 1992 fire , the Undercroft had been divided into smaller rooms ; the area is now opened up to form a single space in an effort to echo the undercrofts at Fountains and Rievaulx Abbeys , although the floor remains artificially raised for convenience of use . The " beautifully vaulted " 14th @-@ century <unk> passage runs alongside the Kitchen Courtyard and is decorated with carved royal roses , marking its construction by Edward III . 
