Four rooms were uncovered which in antiquity occupied the northern edge of the Capitolium terrace. In one a floor of large quadrangular marble slabs was preserved. This fact, together with the recovery of an extraordinary quantity of architectural materials suggests the presence of an imposing public building, with a marble porch or pronaos, that was obliterated in the late medieval period. An altar with lateral pulvini decorated with “gorgoneia”, datable to the Domitianic period and a monumental Corinthian capital must have been part of this structure. It clearly had a major phase in the Flavian period.

Lower down a carpet of marble slabs marking the presence of a stairway perhaps surmounted by an arch was visible. Other arches, of which the pillars remain, marked the crossroads of the decumanus with the cardo of Via De Fraia and, to the east, the crossroads with the cardo of Via S. Procolo.

At the height of the decumanus of Via Duomo investigations revealed six tabernae created in the early imperial period and transformed at the end of the 3rd century A.D.
The eastern stretch of the decumanus of Via Duomo was flanked on both sides by shops and artisans’ workshops of late Republican date. These were enlarged or rebuilt in the Augustan period and given new entrances in the Neronian period.

Lastly, in the area of the foundations of the 17th century palazzo Colonna a series of cisterns and service rooms came to light. In one room a mosaic floor with marine scenes, dating to the first half of the 3rd century A.D., was preserved. Further west stairs led into underground or basement chambers, attesting the large dimensions of this bath complex. On the opposite side of the road a small frescoed room datable to between the 2nd-4th century A.D., was discovered. Below the road a stretch of the ancient sewer was explored.