 Keeps were traditionally built with an entrance at first @-@ floor level , and Rochester 's follows this pattern . A forebuilding attached to the north side guarded the entrance . A stone staircase began on the west side of the keep before turning and meeting the forebuilding , which could be entered by crossing a drawbridge across a gap 9 feet ( 2 @.@ 7 m ) wide . There was another entrance in the west of the forebuilding , and at some point a new doorway was knocked through to the keep at the bottom of the drawbridge pit . The original door from the forebuilding into the keep was protected by a portcullis . 
