Our main motivation for building a virtual version of the town of Tübingen is that in our department we are interested in the capability of humans to navigate through known and unknown environments. Finding your way in an environment means that you have to build some sort of representation of this environment. We would like to learn what kind of information humans store and use for navigation purposes, and how they acquire and access this information. Methodologically speaking this kind of research is a mixture of psychophysics and cognitive and behavioural science. Having access to a virtual model of Tübingen in this context allows us to do highly controlled experiments in a very realistic environment.