Aside from this, we have undertaken two geophysical surveys in the context of the third year of the European Research Council-funded Rome’s Mediterranean Ports Project. The objective of the first was to clarify key questions relating to the exact position and character of the western end of the northern arm of the mole of the Claudian harbour and the pharos or lighthouse island; this is intended to enable us to understand better the properties and dynamics of the harbour, the precise function of which, in the context of the harbour system at Portus, is still the subject of debate. It should also enable us to draw analogies with other port sites in the project, most notably Tarraco (Spain), Ephesos (Turkey), Puteoli (Italy) and Utica (Tunisia), all four of which have been investigated by means of integrated suites of geophysics and geoarchaeological cores. The work was led by Sophie Hay of Archaeological Prospection Service of Southampton (APSS) and Stephen Kay of the BSR. By building on earlier work by Italian colleagues who established the approximate position of the mole with a programme of deep cores in a paper published in 2011 (Morelli, Marinucci and Arnoldus-Huyzendveld, 2011), we surveyed a large swathe of its supposed course with ground-penetrating radar. This revealed a number of possible alignments that are difficult to read, perhaps because the mole lies deeper than the c. 6 m that we suspected, or because the radar signal was attenuated on account of the water table or the salt content of the soil. We plan to calibrate these results in 2017 with a programme of electrical resistance tomography, which will allow anomalies to be plotted to a depth of c. 15 m, and geo-archaeological cores.