The Venice Time Machine project aims at building a multidimensional model of Venice and its evolution covering a period of more than 1000 years. Kilometers of archives are currently being digitized, transcribed and indexed setting the base of the largest database ever created on Venetian documents. Millions of photos are processed using machine vision algorithms and stored in a format adapted to high performance computing approaches. In addition to these primary sources, the content of thousands of monographs are indexed and made searchable. The information extracted from these diverse sources is organized in a semantic graph of linked data and unfolded in space and time as part of an historical geographical information system, based on high-resolution scanning of the city itself.