The 2004 campaign concentrated on the cavea, the perimeter of the building (the summa cavea) and the adjacent portico (_porticus ad scaenam_).

The excavation looked at the orchestra space in the cavea, at the meeting point between the orchestra and the parados. The cavea did not rest directly upon the ground but on an annular tunnel, partially visible at the two ends, through which access was gained to the interior via two rooms. Of the rows of seats only the core in opus caementicium remains, completely robbed of its marble cladding. The side edge of the rows of seats was formed by a balustrade inserted above the corridor and whose presence seems to confirm that the paradoi were open corridors. It can be deduced that the perimeter was not semicircular but ultra-elliptical, and that the orchestra and seating rows were not perfectly semicircular.

The excavation of the summa cavea revealed the presence of a rectangular construction, placed above a crypt at the top of the seating, in correspondence with the monument’s axis. This space was interpreted as the Imperial box, placed in the highest point in order to underline the Emperor’s importance, which combines the religious and imperial functions and seems appropriate for a building conceived, by its nature, to exalt the importance of the Emperor with respect to the rest of the spectators.

In the porticus ad scaenum, the excavation led to the identification of a double terrace that was part of a terrace system that is largely hidden by modern walls that have been built on top of it. Excavation of the upper terrace revealed a raised portico on pilasters with a pavement in opus sectile with a continuous geometric pattern, the first of its type in the Villa, the edges bordered by rectangles placed at a tangent and rhombi, in pavonazzetto, rosso antico and portasanta marble. The central open space was paved with a mosaic in opus scutulatum of the type already present in the Antinoeion. However, the excavation has still not been able to provide a complete understanding of the terrace system, with exedrae and niches containing sculptures described by Ligorio in the 16th century. (MiBAC)

The results of the 2005 campaign will be made known in a monograph due to be published in 2006. (MiBAC)