Note:  Do not rely on this information. It is very old.

Ostia

Ostia, anciently the port of Rome, from which it is six miles distant, was believed to have been founded by Ancus Martius, who also established salt-works here. Originally a trading port, it became in the Punic Wars a naval station, and its inhabitants were exempt, from military service.

Owing to the silting up of the lower Tiber, the Emperor Claudius caused a new harbour - which received the name "Portus" - to be constructed, and connected it with Rome by a canal. This soon rivalled Ostia, which gradually decayed, and was finally destroyed by the Saracens in the ninth century. Both places are now in ruins.