Simulation modeling resembles map-making in an important way: Both aim at constructing devices for orientation and for intervention. The reference to reality or the terrain, however, is far from straightforward. Rather, the result of simulation modeling can be conceived of as a virtual atlas — an object different from a traditional atlas. It consists of a huge compilation of local maps that do not match up to a general overview. Only in a computational setting such an atlas can be used as an orientation device.