ViSIT uses the digital structural change for the increased valorization of cultural heritage: with the Veste Oberhaus (Passau) and the fortress Kufstein two representatives of the castles and residences of the Inn-Salzach-Danube area are opened up for visitors by multimedia installations and a virtual compound system - other locations such as Golling, Salzburg, Tittmoning and Burghausen will also be involved. The museums collaborate with scientific partners from the cultural and computer sciences to create a cross-border digital infrastructure for innovative cultural heritage presentation and assurance. The historic observation tower of the Veste Oberhaus and the tower of Kufstein Fortress are modeled as multi-media adventure sites. At the other locations (as associate partners), cross-site content is created for the participating museums so that a network of interconnected offers is created as a cross-border "virtual museum". Transferable software frameworks (open source) and "best practices" (digitally published) make it possible to expand the network in the future.