It is possible that this cut represents - at least partially - the ancient construction of the drainage channel, which first cut through natural soil and then into the bedrock (a level which was not reached in our excavations due to safety considerations), and that it is this channel cut that extends to the north under the modern Sopraintendenza concrete slab.

This appears to be an ancient cut. We were unable to fully excavate to the bottom of the cut because of safety reasons. The cut appears to continue down and may be another cut related to drainage features (there are at least three drain features in this room previously identified by the soprintendenza). The walls of the cut are quite vertical.