Rome's original harbor was Ostia. Claudius had…

Rome's original harbor was Ostia.

Claudius had constructed the first harbor on the Portus site, four kilometers (two-and-a-half miles) north of Ostia, enclosing an area of sixty-nine hectares (one hundred and seventy acres), with two long curving moles projecting into the sea, and an artificial island, bearing a lighthouse, in the center of the space between them.

The foundation of this lighthouse was provided by filling a massive ship, used to transport an obelisk from Egypt to adorn the spina of Vatican Circus, built under Caligula.

The harbor thus opened directly to the sea on the northwest and communicated with the Tiber by a channel on the southeast.

The object was to obtain protection from the prevalent southwest wind, to which the river mouth was exposed.

Though Claudius, in the inscription which he caused to be erected in CE 46, boasted that he had freed the city of Rome from the danger of inundation, his work was only partially successful, for in 62 Tacitus speaks of a number of grain ships sinking within the harbor during a violent storm.

Nero had given the harbor the name of "Portus Augusti".

It was probably Claudius who had constructed the new direct road from Rome to Portus, the Via Portuensis which is 24 km (15 miles) long.

The Via Portuensis runs over the hills as far as the modern Ponte Galeria, and then straight across the plain.

An older road, the Via Campana, runs along the foot of the hills, following the right bank of the Tiber, and passing the grove of the Arval Brothers at the sixth mile, to the Campus salinarum romanarum, the salt marsh on the right bank from which indeed it derives its name.

In 103, Trajan constructs another harbor farther inland—a hexagonal basin enclosing an area of 39 hectares (97 acres), and communicating by canals with the harbor of Claudius, with the Tiber direct, and with the sea, the last now forming the navigable arm of the Tiber (reopened for traffic by Gregory XIII and again by Paul V).

It bears the name Fossa trajana, though its origin is undoubtedly due to Claudius.

The basin itself is still preserved, and is now a reedy lagoon.

It was surrounded by extensive warehouses, remains of which may still be seen: the fineness of the brickwork of which they are built is remarkable.

The Romans make use of fired bricks, which now become the primary building material in the Roman Empire, and the Roman legions, which operate mobile kilns, introduce bricks to many parts of the empire.

Roman bricks are often stamped with the mark of the legion that supervised its production.

The use of bricks in Southern and Western Germany, for example, can be traced back to traditions already described by the Roman architect Vitruvius.