On the north side of the via Portuense at 17,500 km were discovered three distinct and superimposed paved streets, in use from the end of the fourth century BC to the 16th century AD. The archaeological remains are found in a flat area between the river Galeria, the Tiber and the sea; this zone in antiquity was tied to the Port of Rome. The oldest street was constructed directly on the natural terrain and is formed by a compact and homogenous preparation of chips of tufa, over which are arranged two side curbs, also in tufo, and a gravel roadway two metres wide. The street was in use at least by the end of the fourth or beginning of the third century, while its abandonment is owed to the construction of Street 2, the road of the Claudian-Neronian period. This was also delimited by two curbs probably formed by blocks of tufo, and had a paved surface four meters wide which allowed the passage of two carts at once. This enlarged street, whose construction can be related to that of the Port of Claudius, was abandoned soon after when Trajan, enlarging the commercial port, built a new route. Street 3 is characterized by an elevation of the ground by approximately one meter, contained within two massive boundary walls in opus reticolatum, reinforced by external buttresses and posts at regular distances. On the interior, above the various levels of preparation, was laid a compact and homogenous stratum of gravel. The street now had a width of 6.8 meters, crossed, at more or less regular intervals, by viaducts that permitted the flow of water. This route was used continuously from the Trajanic period until the great floods of the 16th century.