Addition to the length of the north-south running wall on the west side of Room G-8, added after the opus reticulatum wall SU 6187 that it abuts on the north face of the petit appareil wall. May have something relation to the well head, SU 6236, to the east of the SU in Room G-11, but was also added after the well.
Photo from west
G-9 walls
Photo from east