This intervention was undertaken in order to increase the visitor’s route around the archaeological area within the church and monastery of San Lorenzo Maggiore. The well known architectural complex of imperial date was the forum market of _Neapolis_ and developed on a slope on three sides of a rectangle on a north-south alignment. On the _plateia_ of via Tribunali the façade reused the tufa blocks from a terrace system. The reopening of an archaeological trench in the concameration of the double curtain system situated in the south-west corner of the terracing, until now dated to the end of the 4th century B.C., led to the investigation of fairly substantial sample of the _émplekton_ layers. A great many finds dated to the end of the 4th century or the beginning of the 3rd century B.C. However, the presence of fragments of Campana A pottery and amphorae imitating the later Graeco-Italic type suggested a date between the end of the 3rd century and the mid 2nd century B.C. The presence of an earlier level was however attested in the internal curtain of the southern stretch. The cleaning of the western stretch, together with the survey and the excavated trenches provided the data for a reinterpretation of the imperial building phases. These were characterised by a north-south _opus reticulatum_ curtain wall which faced the tufa block terracing. This was abutted by structures built at different times modifying the original plan by creating smaller rooms from a large hall with mosaic floor. Excavation of the south wing of the complex confirmed the presence beyond the cryptoporticus of an ancient perimeter wall, onto which three rooms joined to the south. Of late imperial date they showed the signs of various restorations and reconstructions up until the early medieval period. On this side the investigation of room n.44 revealed stratified occupation phases through to the Angevin period.