Simulation tools are frequently used for the performance evaluations of mobile ad hoc networks. Currently the tools do not take a spatial environment into account, thus providing a poor support for urban scenarios. In this paper, we describe a platform for the modeling of city scenarios. We extend the mostly used MANET simulator ns-2 by the corresponding mobility and wireless transmission models. These models have been evaluated against real-world measurements. By using the tool’s emulation facility, we integrate unmodified applications and real implementations of network protocols. We demonstrate the usefulness of the platform by modeling a mobile application in a simulated environment of Stuttgart downtown. We show that obtained simulation results differ extensively from those with simpler models.