The darsena (Italian for "inner harbour") is a long, rectangular basin (45 x 24 metres), entered through an opening 9 metres wide on the east side. The oldest masonry (opus reticulatum) belongs to the period of Claudius. This was a harbour for auxiliary vessels or smaller ships. The surrounding buildings are at a distance of 6 metres.
The darsena or inner harbour, now filled with earth.
Photograph: Jan Theo Bakker.