The area under investigation is situated within a vast open area, south of the church of S. Stefano dei Cavalieri. The area is of particular interest with regard to urban development in medieval Pisa, as it was at the edge of the political heart of the city and the site of metalworking installations. In fact, the church of S. Sebastiano de Fabbricis stood here, attested from 1074, and demolished to make way for the construction of S. Stefano dei Cavalieri (1565-9).

Two trenches were excavated, sector 100, right by the church, and sector 700 south of the first. Between the 12th and 15th century the area was characterised by the presence of two rather simple buildings, separated by a dirt road 2.60 m wide, and destined for productive, service and residential purposes. Between the 12th-beginning of the 14th century the north building (sector 100) was used for metal working activities, firstly iron and later mainly bronze. Subsequently, in the 14th century, it became a storage facility. The structure had only one floor, no ceiling, and until the second half of the 14th century had low walls and a roof of shale slabs supported by a timber frame. The presence of low walls relates to metalworking, which produces abundant and noxious fumes and thus requires constant aeration, and a covered space not directly exposed to sunlight. With the subsequent changes in function and the transformation into a warehouse, the timber frame was demolished and the walls heightened, whilst the shale roof remained in place. The south building (sector 700), of which two stretches of parallel walls 3.20 m apart and the floor levels remain, was a residential structure. It comprised a ground floor which seemed to have been divided by a series of timber walls, and an upper floor of the casa solariata type. The roof was also of shale slabs. Its collapse, caused by a fire, preserved some partially burnt straw interpreted as roofing insulation.

Following the collapse of these buildings, during the first half of the 15th century, the area was abandoned. The north building was robbed in the third quarter of the 15th century, whilst the south building was robbed at the same time as the demolition of the church of S. Sebastiano and the subsequent construction of S. Stefano dei Cavalieri (1565-9). The area remained an open space the faint traces of which were attested by the late 17th century building site for the enlargement of the church and the creation of an area with trees.