This feature seems to be both a drain cover for a deep drain running E-W across the area (see SU 5772) as well as being a walking surface. Its surface is slightly lower than the threshold stone to the South (SU 5740) and slightly lower than the roughened face of wall 5741, however, the slabs which make up the feature have probably subsided slightly over time (see, for example, the fact that they are fragmented). These slabs' relationship to the surface of the floor to the North (SU 5726) is unclear. There is a gap and a step up in elevation to that floor perhaps suggesting that a stone or stones forming a finished step have been removed.