An archaeological investigation was undertaken on an area of circa 7.500 m2 situated at No. 26 via della Moscova. This led to the identification of structures belonging to the church of S. Carlo and the associated monastery of the Barefooted Carmelites, attested in this area from 1614 onwards by historic and cartographic sources. These structures survived and were reused as warehouses, an arsenal and tobacco factory during the 18th and 19th centuries. They were finally destroyed by war-time bombing in 1945. Two distinct metal working zones were identified within the excavation area. The first revealed the badly preserved remains of a large circular furnace, linked via a small channel to a pit. This installation for founding was created inside the wall of the church of S. Carlo, which had already gone out of use. It is known that founding for both refining purposes and in the work of gold and silversmiths leaves a residue of precious metal inside furnaces and crucibles, as well as in the waste products. This residue was carefully recovered. The archaeological and analytical data is precisely confirmed in a series of documents conserved in Milan’s State Archive. These documents describe the transfer from Austria to Milan in the second half of the 18th century of artisans who were highly specialised in the working of precious metals. The installation of a metal working structure that was technically avant-garde for the period must have been related to the nearby mint. In the following period the SE zone must have housed other metal working establishments as a water/wind driven bellows was installed there. This was an automatic bellows for use with a forge or other metal working installations; it was brick built and had a cylindrical central structure. Probably invented in Italy in around 1660, it was a simple blowing apparatus, economical and efficient to run which soon substituted the more costly and delicate bellows in pre-industrial and industrial installations.