This computer graphics project, provides a chronologically ordered sequence of digital models reconstructing the Vatican hill, the Campus Vaticanus (now the Borgo) and the south-east slope of the Janiculum. Our work focuses on this area as a unified topographic site and seeks to analyze and to depict how it has been altered by successive buildings located on the site from Antiquity to the present. For us, the buildings are primarily volumes impacting the topographical character of continuously evolving site. Our focus, therefore, is on process and on change.

The work presents challenges of several kinds, which we propose to present as problems of historical reconstruction on the one hand and representation on the other. The ultimate question to be resolved is the hypothetical reconstruction of the original topography of the area before any human intervention. Although this is the starting point for all later alterations, it is, from the point of view of research, in reality the end point since the original topography can only be deduced by conceptually removing the present structures, step by step, in reverse chronological order. Each of the present buildings stands on a site to some degree determined by earlier architectural interventions and by natural forces such as soil erosion. Definition of these factors permits the hypothetical restoration of a previous condition of the site. Our work considers the site in some fifteen chronological periods, delineating units in which the most notable topographic changes occurred. Within each period we develop one or more hypotheses about the location, character and effect of all structures known to have existed including roads, aqueducts and gardens as well as buildings. We have experimented with various techniques for illustrating the passage from one state of the site to the next, such as transparency, animation and color coding.