The Fortification System of the City of Urbino: The Case Study of Valbona Gate from 3D Surveys to GIS Applications for Dynamic Maps

The city walls of the city of Urbino, originally Metaurense Urvi-num, today represent the result of an evolution that has antique origins, from protohistoric settlements to the first Roman ruins, up to its current conformation, expression of the important Renaissance period. We present a study of documen-tation, survey and analysis of the various parts of the walls, analysed in their entirety and in individual elements, among these we focus on the main access gate to the historic centre, Valbona Gate. The integration of avant-garde technol-ogies during all the phases, from the survey to the graphic rendering, up to ad-vanced management with GIS instruments allows us to have a picture of the ar-chitectural reality both of the present and the past, fundamental for scheduled maintenance and for planning future conservation interventions. The geometric and morphological survey brought the process to completion with the problems relating to deterioration, the understanding of the situation of the pathologies and the descriptive dimension of the architectural elements in a complete bi- and tri-dimensional GIS system that allows us to take advantage of a complete series of processing and statistical assessment capabilities. The project is part of a wider program of research on the walled city of Urbino, wherein the analysis of the city walls integrates with the diachronic analysis of its expansion and the geomorpho-logical context in which it is found as well as a 3D City Model and the analysis and management of the built environment, current and archaeological.