A cut for unknown purpose. Unclear whether it is related to later, post;abandonment activity like robbing; or to the second (concrete) phase of the building; or to the earlier, original ashlar phase, contemporaneous with the use phase of the tufo slab floor 5321. If this last is the case, then this hole may be associated with holes 5501, 5502, 5503, and 5504, immediately to the north, all of which may have accomodated some sort of architectural feature(s) in the "courtyard"