Near the ruins of the abandoned town of Ostia Antica - and only the shortest of distances from
Rome's main Fiumicino airport - it's occasionally possible to visit what remains of the unusual
hexagonal harbour at Portus, which some are lucky enough to glimpse from the plane.
If you weren't, take a look in GoogleMaps, and search for.... "lago di traiano"
It's thought that this area - developed successively by the emperors Claudius and Trajan -
was linked to Ostia by an immense canal, traces of which archaeologists have unearthed