A preliminary trench dug as part of the work for the construction of a lift shaft in the courtyard of the apartments in via Domenichino n. 7 revealed the presence of two Roman walls forming a right angle. The walls, on an ENE-WSW and NNW-SSE alignment, were faced with white plaster that is only partially preserved. They had been razed and stood to a height of 0,30 m above the ground level in the courtyard. The trench measured 1,90 × 2,10 m and reached a depth of 2 m below ground level, however, this depth did not reach the floor level relating to the walls. The wall on an ENE-WSW alignment extended for circa 2,10 m and continued beyond the trench edge; it was 0,55 m wide and had a large opening at circa 1,70 m from the top. The second wall had a maximum length of 1 m as it was cut by the perimeter foundations of the apartment block. This wall also had a semicircular opening. It is possible that the walls belonged to the same building complex, of which a room was found in 1906, in the area between via Domenichino and via S. Martino ai Monti. This hypothesis is based on the topographic contiguity and analogies relating to construction technique, wall thickness and type of wall facing. Moreover, analysis of the data from excavations undertaken between the end of the 19th and mid 20th century, an examination of literary and epigraphic sources and the observation of the relief inscribed on several fragments of the Severan marble Forma Urbis have led to the delineation of the urban layout in the area within which the structures in the trench are situated. (Mariarosaria Barbera – Valerio Carozza)