On December 3rd 2010 the application Colonia3D was officially handed over to the Roman-Germanic Museum (RGM). This application provides a high-detailed virtual 3D reconstruction of the Roman Cologne. The interactive application is based on technology developed by the research group 3D Geoinformation at the Hasso-Plattner-Institute. It enables users, e.g., to freely explore the antique city and compare selected places with today's Cologne. Already since March, Colonia3D has been used by thousands of visitors. After the successful test run, it now becomes part of the museum's permanent exhibition.