The archaeological area , where the remains of the ancient Forum of Neapolis are visible, is the most important archaeological site in the historic center of Naples .

A real archaeological area about 10 meters deep. Inside the eighteenth-century cloister part of the macellum, the Roman market, is visible.

The lower levels of the excavation highlight the complex structure of the entire area, a series of nine shops, each consisting of two barrel-vaulted rooms open to the street, where commercial and artisanal activities took place.

In the San Lorenzo museum complex there is also the Basilica of San Lorenzo, one of the oldest in Naples. With the advent of Charles I of Anjou , the Basilica was the first church to be rebuilt according to the unmistakable French Gothic style , introduced by the workers following Charles I. The current plan of the Basilica has a single large central nave, Apse and 23 side chapels.

The Museum of the Opera of San Lorenzo Maggiore is instead set up in the sixteenth-century rooms around and in the civic tower . It presents a real cross-section of the history of Naples from the classical age up to the nineteenth century and illustrates the stratifications present within the monumental complex, starting from the Greek-Roman era up to the eighteenth century.

In the middle of the east side of the cloister there is the entrance to the Chapter Hall , enriched by a Gothic portal from the second quarter of the fourteenth century, flanked by splendid four-light windows and surmounted by a low-arched lunette.

The Sala delle Virtù by Luigi Rodriguez is made up of a grandiose rectangular room, an elegant Swabian-era vestibule which, according to Celano, was once frescoed like the cloister. The frescoes on the walls and vaults date back to the early 1600s : they were painted by Luigi Rodriguez , during the reign of Philip III, on behalf of the viceroy Ferdinando Ruiz di Castro and Andrada.