Parte di ampio magnifico Porto all'uso degli antichi Romani, ove si scuopre l'interno della gran Piazza pel Comercio... (Part of a spacious and magnificent Harbor for the use of the ancient Romans opening onto a large market square...), from "Opere Varie di Archiettura, prospettive, grotteschi, antichità; inventate, ed incise da Giambattista Piranesi Architetto Veneziano" (Various Works of Architecture, perspectives, grotesques, and antiquities; designed and etched by Giambattista Piranesi, Venetian Architect)

In the dedication to his first publication, the Prima parte di architettura e di prospettiva of 1743, a series of imaginary views, Piranesi wrote that his observations of the vast remaining piles of marble and the immense spaces once occupied by ancient buildings had filled his spirit with magnificent images. Since he despaired of anyone financing such grand structures, he had decided to share his visions through means of prints. In the Parte di ampio magnifico Porto, an addition to this series of architectural fantasies that was created some years later, we witness one of his most visionary reconstructions of Rome's former grandeur.
While an impressive stairway had recently been constructed at the Port of Ripetta in Rome—perhaps one of Piranesi's inspirations in creating a design for a port—the combination of buildings illustrated in this etching could never actually be built. Among the spatial ambiguities, apparently deliberate, the three curving walls, as of a giant amphitheater or the interior walls of the Pantheon, do not relate logically to each other. In the inscription plate which Piranesi added to the second state of the print, many of the features of the port are explained, such as the rostral columns that commemorate naval victories, and the altar to Neptune, from which clouds of incense issue ceaselessly. The idea of landing at such a splendid port is thrilling, although it would be nicer if Piranesi hadn't informed us that the liquid pouring from the lions' head spouts is sewage.