Within the valorisation project of the Etruscan Necropoli, a UNESCO site in Cerveteri – the ancient Caere city developed between the 9th and 2nd century BC, 40 km far from of Rome – we realised a unique GIS application, called SITAC, that responds to knowledge, project and management needs. The main project aims to preserve and promote cultural heritage and to grant tourist access to the archaeological, naturalistic and landscape resources: a light electrical train circuit will become the accessibility backbone of this sophisticated complex of more than 500 tombs, often superposed, green areas, viewpoints, almost 5 km of narrows etruscan roads developed in volcanic rocks. SITAC project started with the 3D analysis performed on recent aerial photos producing an High Resolution DEM (2x2 mt) of the area. The largest part of this area is still under a thick vegetation coverage and many ancient structures have to be excavated. The project is based on the organization of several thematic layers, vector and raster, in GIS environment. Work proceeded with the integration of different data: survey measurements, dGPS data, photo-interpretation of recent and historical aerial views, historical cartography at different scales, pictures campaign with metrical information and other multimedia documentation. The integration process has been developed giving a reliability order to the data. We assumed survey measurements as the most accurate ones, on which others data have been referred and adapted. Than, the dGPS data, affected by low precision under the vegetation coverage, have been used only for xy mapping while for the z value, we used the surveys points as Ground Control Point (GCP). Again, other features, on different themes, have been referred to the map obtained from survey measurements and dGPS data. We integrated into the SITAC the information given by the historical cartography, the tombs recognized by photo-interpretation, the tabular data obtained by the archaeological outcrops field classification and the photographic documentation of the site. The first results of surveying and GIS application are: the tourist paths definition, the definition of alternative routes for a light train, the base maps and vertical views for the execution of primary intervention on the site (cleaning monuments entrances, paths preparation, security and monitoring systems, wood structures, emergency restoration programming). This sets SITAC as the main system in planning, projecting, evaluating activities concerning the area and as a useful support to decision making processes. The Next step is the GIS integration of the archaeological database, supplied from experts and institutions involved in the project. Georeferencing this documentation is the first step to offer on site the desired descriptions through mobile devices and smart panels – with texts, maps, pictures, audio files. This database will be devoleped referring to three kind of users: 1) expert users for technical purpose: historical analysis, cataloguing, excavation, conservation and restoration plans, risk evaluation; 2) for direct support to tourism, with the full representation of itineraries, facilities and services; 3) remote users, for communication and promotion purpose with interactive and multimedia solutions: virtual tours and museums, cd-rom, webgis application.