 <unk> to the gatehouse is the 13th @-@ century keep . A keep contained the main domestic accommodation in a castle , usually high @-@ status , and also provided the last place of refuge if the surrounding enclosure fell during an assault . Brougham 's keep has a square plan and is between 19 and 20 metres ( 62 and 66 ft ) high , although originally would have stood taller . Access to each floor was granted by a spiral staircase in the north @-@ east corner , with each floor consisting of a single large room . The garderobe was located in the north @-@ west corner . It had long been assumed that the keep was built in the last quarter of the 12th century due to its simple design ; the square design , use of narrow buttresses at each corner , and entrance through a forebuilding are consistent with other keeps built in the late 12th century . By the 13th century , Brougham 's keep would have been old fashioned compared to the polygonal structures introduced in the 13th century . However , historian Henry Summerson who assessed the historic documents for the castle concluded that construction could not have begun earlier than the first quarter of the 13th century . The wooden floors no longer survive , and the use of the rooms in the keep is mostly conjectural , however it is likely that the ground floor would have served as a storage room , with the first floor being used as a hall and accommodation for the guards , and the second floor providing rooms for the lord . A final fourth storey was added in early 14th century . The keep would have been entered at first floor level , through the east side where it was abutted by a forebuilding . Despite the keep 's importance to the castle structure , little survives of the building today . 
