The Church of Notre-Dame at Saint-Lo was bombed by the Allies in 1944. It was totally rebuilt after the war, but in the process it lost its original façade and towers. The church has become a symbol of the Second World War, and its true history has been replaced by a romantic myth. However, a virtual reconstruction of the church, available through an interactive terminal, offers to the general public the opportunity to experience simultaneous levels of space and time. Thus every visitor can discover the original historical and architectural details of the church in 3D, in real time, in interaction with a virtual model and also guided by a virtual human. The essay describes the evolution of the project that will be inaugurated in September 2011. Key words: Historiography; 3D; Multimédia; Augmented reality; New museology; Digital Public History.