This article describes the discovery of an area of habitation of the domus of the Valerii, a family with yen ancient origins, said to descend from the first consul, Valerius Publicola. The excavation, undertaken in 2005, investigated deposits beneath the Ospedale dell'Addolorata where, in the early years of the twentieth century, the construction of the southeast block destroyed the upper levels and a complex row of structures along the northern side, towards via Santo Stefano Rotondo. Since the middle of the sixteenth century, uncontrolled excavation and research have recovered an important inheritance of knowledge and of high-quality finds — often sold or dispersed in some way. The excavation has revealed part of a frescoed corridor, 3.8 m wide and originally c. 3 m high, with a pavement in black mosaic, with windows opening onto a garden. Of this imposing structrure, datable to the late Hadrianic period, various phases of building activity, abandonment and reuse have been identified, amongst which the construction of a hidental is of particular interest.

The stretch of the Aurelianic Walls from the Porta Latina to the Porta Appia comprises twelve towers linked bv curtain walls with covered walkways. The surviving state of the monument is described in detail. The individual phases (from AD 275 to the present) are distinguished through the analysis of their construction techniques, archive drawings and photographs of vanished sections, papal coats of arms, and inscriptions (in pencil or graffito) recording more recent events. When the entire circuit was doubled in height during the Honorian phase (AD 401–3), the floors of the towers were built at a considerably higher level than the rampart walkways, so as to exploit fully the type of siege machinery (halhstae) located in the towers' upper chambers. The Honorian loopholes, for the use of archers, reveal a long and complex history: undergoing modifications during construction, they were subsequently blocked to prevent the illegal traffic of goods (and the avoidance of customs dues), and were finally reopened and modified once again for the defence of papal Rome. The modern restorations of 1930–67 are examined critically. The need for immediate restoration and sustained maintenance to guarantee the monument's structural integrity is now clear. It is to be hoped that a direct link (with visitor access) will be provided with the ‘Museo delle Mura’, which was set up in the neighbouring Porta Appia in 1970.