We describe the environment and motion systems used in a parallel, discrete event large scale wireless simulator. The simulator is capable of supporting user motion on multiple environment types (different types of streets, buildings etc.) and provides a unified and intuitive interface to users whilst being efficient for the systems that make use of it. This is achieved by making use of a hierarchical environment description. With this approach, users can provide different levels of detail as required, whilst the motion systems have a simple interface to interrogate the environment. As there is a close coupling between the environment and the RF data required by the wireless simulator (which is considerable in size), this too is represented in a hierarchical manner. This allows a more efficient use of system memory with only the data that is required being loaded.