The Pre–Trajanic Harbour (Porto di Claudio)
Rome was not provided with a purpose-built sea port until the mid 1st century AD, when the Emperor Claudius began building the artificial harbour of Portus in the delta of the Tiber, a few kilometres to the north of the river port of Ostia. The site is referred to by archaeologists as the Port of Claudius (Porto di Claudio). Claudius' engineers oversaw the construction of huge curved concrete moles that stretched out into the sea to enclose a massive artificial anchorage (Fig. 1). One of these served as a platform for a monumental lighthouse in imitation of the great pharos of Alexandria. On its landward side, the harbour was provided with a series of wharves and porticoes to accommodate traders and the storage of goods in transit. It was also connected to the Tiber to the east by two canals. This site was a curious choice since this stretch of coast is very exposed to both wind and currents, while the Tiber itself constantly deposits silt that would clog up the harbour unless it was continually dredged. Moreover, its exposed seaward location, and the huge area that it enclosed, led to a major disaster in AD 62 when a great storm wrecked 200 ships moored in the harbour.
Interpretative reconstruction of the geophysical and structural evidence for the layout of the Pre-Trajanic port
