The underwater archaeological investigation undertaken to make a graphic record of the visible structures of the Roman port of Misenum has been concluded. Underwater in the dock area, closed to the north by Punta Penna, it was possible to follow the traces of the quay built in opus caementicium and equipped with large mooring bollards. Two series of eight pilae stretched out from the quay towards the centre of the bay. The easternmost delimited the port entrance in correspondence with the pilae of Punta Terone, whilst the westernmost fronted a second quay with a continuous foundation stretching out from Punta Saparella. This quay exploited the line of a tufa bank and was constructed with the help of wooden shuttering/formwork, of which, in some cases the planks and external fixing system were identified.

In the eastern most section, along a clear disjunction in the height of the structure towards the interior, a second wall parallel to the quay seemed to delimit a road. Moreover, along the entire submerged wall of the eastern sector there were the surviving remains of dividing walls built in order to create a series of rooms. Further on were the remains of more opus caementicium walls, perhaps part of a lighthouse or watchtower. Lastly, Punta Penna is crossed by three tunnels. The eastern tunnel cannot be inspected as its entrance is obstructed by collapses, whilst the central tunnel can be accessed from the quay and therefore was certainly practicable on foot, joining the two sides of Punta Penna. The third tunnel is larger and cuts through the headland in the easternmost sector and was probably flooded to enable the passage of small boats. As regards research on land, to date work has concentrated on the so-called Grotta della Dragonara, an enormous cistern excavated out of the tufa at the foot of Capo Miseno and originally used to supply Roman ships.