In June 2014, Rome University, in collaboration with the Special Superintendency for the Colosseum, the MNR and Archaeological Area of Rome, resumed activities inside the Flavian amphitheatre, as part of a project aiming to document the post-antique use of the monument.
In 2011-2012, the excavation of cunei III and X was completed. Therefore, in 2014, a new area was opened in cuneo IX.
Here too, the removal of the paving slabs during the 12th century caused the loss of the stratigraphy that had built up in late antiquity and the early medieval period.

However, these phases were preserved inside the sewer pipes, which had kept a complex stratigraphy intact, dating from the 2nd century A.D. onwards.
The evidence showed that during the later medieval period each cuneo underwent independent and differing changes, including many different types of use.
In this cuneo, the first occupation evidence found, post-dating the removal of the ancient paving, related to the division of the space into two parts with the construction of a transverse wall. Later, this was almost completely removed and substituted by another structure built using reused materials and moved back about 50 cm towards the arena.

The restructuring eliminated the area’s earlier function as a passageway, probably transforming the space into one of the numerous cryptae that are mentioned in written sources and which characterised the monument between the 11th and 13th centuries. The traces of housings in the ancient walls of travertine and tufa blocks attest the use of the outermost part as a stable or storeroom.
In the same phase as the one that saw the construction of the dividing wall, a wattle and daub structure was built in the outer room, running parallel to the west wall of the amphitheatre. However, its function, certainly linked to the creation of the crypta, remains to be clarified.

During the 14th century, the ancient structure of this cuneo, like the adjacent one, was systematically robbed of the travertine blocks. With the consequent collapse of the sidewalls, and probably most of the roofing, the crypta fell into disuse, the transverse wall was demolished and the space was once again used as an entrance leading into the arena from the outside.
This function remained throughout the modern era, until the substantial transformations linked to the excavations and restoration of the Napoleonic period.