Wall 5318 is an exterior wall on its north face as evidenced by the lack of abutting walls on that side. The wall appears to be associated with a floor level on the south side that was about 15 cm above the visible floor surface, as seen by the height of the wall foundations. The wall is built above the level of the earlier ashlar walls as well as the parallel opus reticulatum wall 5367 and the tufo curb 5340. It is therefore associated with the latest phase of occupation.