The basin and associated structures

The Project’s survey has added considerable detail to what was previously known about the harbour focused around the new hexagonal basin. For example, at the centre of the side lying opposite the entrance to the hexagon is what appears to have been a rectangular temple surrounded by a porticoed sacred precinct: the temple may have been dedicated to Liber Pater Commodiana. It would have been immediately visible by all ships entering the hexagon. In front of it was supposed to have been a colossal statue to the emperor Trajan. A double row of warehouses flanked either side of the temple precinct. By contrast to this, the southernmost side of the hexagonal basin served as a major transhipment area for cargoes heading to Rome. Warehouses open onto both the hexagonal basin which lies to the north, and on to the new Trajanic canal to the south, allowing cargoes to be unloaded from sea-going ships, stored and then on to barges. A major component of these cargoes would have been earthenware containers, known as amphorae. The cargoes would then have been towed upstream to Rome at different times in the course of the year. The large hill of amphora sherds at Monte Testaccio, on the south side of Rome adjacent to the Tiber, is witness to the scale of this movement. These amphorae came from Spain and North Africa.

The most enigmatic side of the whole hexagon is side VI, the site of the so-called "Imperial Palace" ("Palazzo Imperiale"). This is an impressive monumental complex whose remains still stand to a height of at least two stories. Reports by 19th century archaeologists described the underground vaulted portico (cryptoporticus), colonnades, baths and possible theatre, as well as noting high quality sculptures and inscriptions. The site is of key importance since it lies in a unique position over-looking the outer basin of the Port of Claudius (Porto di Claudio) and the hexagon of the Port of Trajan (Porto di Traiano). Our work has added more detail to what is known although there is little evidence to suggest that it was a palace. The Trajanic layout of the area lying between side VII of the hexagon and the Canale di Comunicazione Trasverso is difficult to fully understand. It formed a key part of the pre-Trajanic port, and became a major focus of occupation in the late antique period, when the Basilica Portuense was constructed. All of these activities have generated a complex palimpsest of archaeological features whose geophysical signatures are difficult to disentangle and interpret. Nevertheless, it does seem that there was a large and complex rectilinear complex here into which the Basilica Portuense was later inserted.