This channel runs to the south of the city and is 45 metres wide. It is known as the Fossa Traiani or Traiana, but it was made by Claudius. In the Middle Ages it was called Fiumicino ("Small river"), as was the modern village at the mouth of the channel (the river leading to Ostia was called Fiumara Grande). The Fossa created an artificial island between Ostia and Portus, called Isola Sacra ("Sacred Island") in late antiquity, and earlier also Assis.
Vaults in the north bank of the canal, discovered during work on a road
and bridge leading to the airport. Testaguzza 1970, p. 183.