Ultramundum Foundation is producing, in collaboration with SOFIHA collaudi srl, Synarea consultants srl and Vision srl, the virtual model (P.I.D) of the city of Rome. The model offers a free 3D interactive exploration of the whole 500.000 buildings of the city and of 30 monumental areas like the Colosseum, the Trevi fountain, Piazza di Spagna, the Capitoline hill and many others. This will be the first complete three-dimensional model of the contemporary Rome explorable in real time. Until today, only portions of cities or small towns have been modelled with technologies like the one used, due to the prohibitively huge amount of data to process to generate a three-dimensional model of an area with hundreds of thousands of buildings, like the one of Rome. The Rome city PID allows for exploration on a standard personal computer with a modern video card. Esoteric hardware is not necessary. Thanks to the patented UltraPeg technology, the Rome PID offers an interactive fly on all the city and allows for a descent to ground level in any street to walk among the buildings. Getting altitude the speed increases accordingly to allow for an exploration experience easy and really natural. Every city building is present, with a prism precisely defining the ground perimeter and height. In this way the volume is perfectly modelled. The roof and facade are created by so-called 'staminal Tabulae', capable of procedurally generating complex 3D models and texturing. In this first step, precise models with high realism of 30 important city monumental areas have been inserted. In the second phase, each building will be modelled in every detail. Many other uses are possible and will be presented, with applications in the fields of projects making and planning, of tourism, of study and promotion of the city image. The PID is not a closed software, but a platform that can be used in many different fields and can be expanded and modified at will. Any Tabula, the data structure at the root of Ultramundum Foundation's UltraPeg technology, can hold multiple data types. For the Rome city model, informations on buildings positions, root maps, monumental areas placements and specific schematics have been imported from Autocad files and other databases. The Autocad file importer, called UltraTools, allows for fast and almost automatic acquisition of public databases, converted in a very short time to three-dimensional elements. All these data can then be explored in real-time. The Foundation can arrange interactive demonstrations on request, because this product can not be freely distributed yet.