The collection consists of historical records and a corpus of 269 black and white photographs taken during the construction of the Milan subway. Collected by Luigi Zaretti, chief engineer of the subway Line 1 between 1957 and 1963 for the company M.M., the collection consists of seven classifiers of photographs and a box that contains documentation concerning the Zaretti's activity: plans and sections of the stations, maps, financial and structural calculations, such as studies of developments of constructive procedures for tunnels, surface studies of underground prefabricated structures implemented by the excavations in the trenches, as well as the dossiers with the technical description of the underground structures by Alpina S.p.A. (Milan). Photographs were taken by various agencies during the work, including Publifoto, Cera Foto Servizi and Photo News Giancolombo directed by Gian Battista Colombo.
