As mentioned above, this unit probably should have been further distinguished, as it consists of three separate features: two tufo blocks, which are not clearly connected with one another, and a short stretch of opus mixtum wall, which is aligned E-W and seems to be in its original position. The blocks are of unknown purpose, and may be related to the later reorganization of the space immediately to the west (Room 17), possibly similar to block 5746. The concrete feature seems to be the only remaining trace of a wall that further delimited and reorganized the northern space of the small courtyard, for an unknown purpose, as no other features of a second phase are preserved anywhere to the west or north in the courtyard.
Opus mixtum wall running north-south in NW corner of Room 17 (5744), Concrete superstructure on top of tiles 5577 (5745), Single tufo block west of wall 5744 (5746), Tile floor at W limit of room 17 (5577), Cluster of concrete and broken tufo blocks west of 5575 (5747), and Opus mixtum wall S of room 17 (5575)