During work to extend the Star Hotel Rosa archaeological investigations were undertaken in the area occupied by the remains of the Republican city walls and the fortifications of Maximian.
Phase I (1st century B.C.): holes of uncertain function, levelling deposits and a ditch connected to the Caesarian city walls.
Phase II (1st century A.D.): foundation trenches for a residential complex abutting the city walls: the high level of their decoration is suggested by their wall plaster, of Augustan date.
Phase III (2nd century A.D.): demolition of previous complex and construction of new buildings. The remains of a structure with opus signinum floors and a pottery or tile kiln, which used the water from the nearby ditch, came to light. Three rows of wooden palisade were constructed in the bottom of the ditch, perhaps to provide support for an embankment protecting the Republican walls.
Phase IV: the phase III structures were removed and the ground level raised. A dump of high quality painted wall plaster (mid-second half of the 1st century A.D.) may have come from the demolition of the phase II buildings. The west side of the embankment was progressively filled. Post holes arranged in a circle and depressions lined with fused metal indicate craft activity.
Phase V: an increase in ground level prior to a phase of removal and demolition.
Phase VI (end of the 3rd-beginning of the 4th century A.D.): removal of the kiln. Large holes were revealed containing abundant flakes of bone and hair pins (3rd-4th century A.D.) relating to a craft activity.
Phase VII (late antique period): new buildings were constructed, others were demolished. A hearth surrounded by three rows of bovine metacarpal bones, inserted vertically into the ground with the heads sticking out and partially burnt is part of a furnace used for iron founding in the production steel. Numerous post holes relate to movable structures linked to craft activities.
Phase VIII (medieval period): structures with wells and cisterns are built on the organic and rubble deposits covering the area; two cisterns were found.
Phase IX-X (15th-20th century): structures are built equipped with wells and tanks and modern cellars; rubble dumps attest the demolition of the structures pre-dating the paving and laying out of the present piazza. (Anna Ceresa Mori, Delfina Consonni, Carla Pagani)