The first reference to the city as "Centocelle" (100 Cells) appears in a letter from Pliny the Younger, in which he relates being called to the council of the emperor Trajan "at Centocelle".
This name which is said to be derived from a building or small storehouse equipped with numerous rooms, but built, however, in a later epoch) probably refers to the series of small inlets which, interrupting the rocky coast, provided secure landing places for ships.

The name existed perhaps before the arrival of Trajan; the emperor had a villa built where generally is identified as the place on the panoramic Belvedere hill (l km east of the existing city) and he is said to have begun work on the port.

Trajan imagined this landing place as the true "Rome Port" from the moment when the port of Ostia, at the mouth of the river Tiber, was declared insufficient and technically inappropriateand in which even Trajan took part creating the internal hexagonal dock.

The testimony of Pliny continues with the description of the dockyard which can be seen from the emperor’s villa; the left arm has already been finished, and work is being done on the right, while the entrance to the port is being constructed with the foundering technique of barges loaded with blocks of stone, creating an artificial barrier which breaks the fury of the open sea .

"With time -adds Pliny - it will seem to everyone as if an "island" has been formed naturally. Built in 106 A.D., perhaps by the celebrate architect Apollodoro, the new port divided the function of centre of supplies for Rome. It was less favoured, however, compared to the others because of the major distance from the city. So at an early time it became above all a base for the imperial war fleet.

The particular form of the port is attributed to Apollodoro, which would also have been complete by architectural adornments such as structures and statues. As a result of this enterprise, the area which had already been inhabited during the etruscan era, became more populated and so the construction of an aquaduct became necessary.

The Emperor Hadrian brought to completion many initiatives undertaken by Trajan, finishing both the port and fortifying the Terme Taurine.
Later, Rutilio Namaziano descrive the port effectively as" an aquatic amphitheatre defined by jetties, from which the artificial island protects the narrow straits.