In 1748, the architect and surveyor Giambattista Nolli mapped an abstract reality of the city of Rome. As a challenge to the inherited projections, it represented the city mixing streets, halls, corridors, churches, baths and markets as part of a unique public space network. A new way to design public space and rethink the whole urban system was opened by the possibility of containing in these representations a single layer with all kinds of public space (including the interior of public buildings). Despite this, Nolli’s plan remained as a useless instrument since the hegemony of automobile mobility appeared as a pre-eminent system. This research tries to understand how the application of the ancient cartographies’ methodology can improve the pedestrian mobility of historic cities by means of enhancing the graphic value of the system of Giambattista Nolli. Nowadays, free public space is represented as empty and built ones, as solid. This proposal would revert this reified conception of the city, understanding this baroque representation as an instrument of identification and assessment of the transitional heritage. The clues unveiled by Nolli seem to be able to integrate the plans of public buildings within the urban tissue, which would result in a step towards the full integration of cartography and mobility. The success of the comprehensive tools offered by large servers such as Alphabet inc. (Google) or Bing Maps confirm the suitability of the combination of new technologies and Big Data with urban planning, reaching the synchronisation of Smart Cities. Nowadays, open public space can be ‘walked in’ from any electronic device, consequently, the application of the “Nolli methodology” would implement the model of urban geolocation with the assimilation of inner public spaces. In the creation of a great global map of the public space, a chimaera could be intuited. This would be discussed within a tangible reality: every open public space is already housed in the Big Data and it is accessible through geolocation tools. The inclusion of the of the public buildings’ interiors would contribute to develop a greater permeability between city and citizens. Furthermore, this representation would optimize pedestrian travel times and would be able to expand the geolocation system network as a documentary repository.