The momentum created by the sequence of scenarios evoking port complexes reaches one of its highest points in this plate. With the triumphal arch awkwardly placed on the landing of a medley range of staircases, Piranesi cited a pair of works by his rival Luigi Vanvitelli (1700 – 1773) in the port town of Ancona, central Italy: the Lazzaretto, at pope Clement XII’s behest, and the Arco Clementino, in the same pope's honor. The first, also called Mole Vanvitelliana after the architect, was a building complex designed as a quarantine station in a project that also included a new wharf. The Lazzaretto was finished in 1738, although the wharf took a little longer, and was finished in 1781. The Arco Clementino (Clementine Arch) was proposed and designed by Vanvitelli to pay homage to the pope, his patron.
Many nautical and port references that Piranesi used in the Carceri are commentaries on the design for Ancona, a city with a rich history that began in antiquity. Vanvitelli’s redesign was a large-scale project that required the archaeological, architectural, and hydrological knowledge that Piranesi claimed to himself. Ultimately, Piranesi must have greatly envied the opportunity to work on such magnificent projects. The conflict between Piranesi and Vanvitelli was motivated a great deal by Piranesi’s envy. The patronage system largely favored Vanvitelli, the son of an acknowledged artist with important contacts, and the hostility between Piranesi and Vanvitelli grew stronger and became mutual along the years.
Ports and nautical elements, therefore, represent more than a familiar environment that connected Piranesi to his hometown Venice. They were also a channel for Piranesi to release his resentment with Vanvitelli. In contrast to the professional failures that Piranesi endured in his first years in Rome, Vanvitelli was already a successful architect in the 1740s, who could already show in his portfolio these significant commissions.
The spatial sophistication of the architecture in this plate is monumental. Piranesi wants to prove his capability of designing utterly complex structures and convince us that he would be able to formulate architectural solutions substantially more advanced than his enemy Vanvitelli.