Detecting the non-existent: knowledge, analysis and reconstruction. The Campitelli district and the demolition of the late nineteenth century

Rome is a city extremely complex because of the millennial stratification and overlapping of historic buildings. A compact urban and sinuous fabric. However in some cases this property was ripped open by demolition, sometimes necessary, but often quite invasive. The virtual reconstruction of the cleared areas is a topic of great relevance to the preservation and knowledge of cultural heritage. The study area is the one at slopes of the Campidoglio, which was demolished at the end of ‘800 for the construction of the Vittoriano and the open space of Piazza Venezia. The detailed archival research, digitization and the meticulous virtual reconstruction make this research important from many points of view: knowledge, media, museum, but most of the historical memory recovery. The project presented here, still under development, born from overcoming these limitations through activities aimed at utilization of the potential of IT and digital way to develop new research directions. Especially trying to achieve two specific objectives. First, the three-dimensional modeling of significant parts of the historic city, especially those portions of the city that were demolished in the demolition previous six centuries. Secondly the definition of digital urban museum tours, which are useful to understand the state of the places before the demolitions. For this reason we decided, given the minutia of details of the reconstruction, to introduce the term “non-existent survey”. The Cadastre Pio-Gregorian, first general register of the Papal State on particle base, has been the main reference for the recomposition of the original urban fabric