This chapter concentrates on the studies of navigation within a moving environment. It begins by reviewing the rationale for studying navigation on a moving substrate. It then outlines the data suggesting that rats organize their behaviour, memories, and place cell discharge in multiple spatial reference frames. Experiments are also described which indicate a specific role for the hippocampus in organizing information in distinct reference frames. Furthermore, the concept of a reference frame is extended to formalize several cognitive phenomena that require the spatial computations of navigation but do not require movement through the moving environment. In general, rat navigation and spatial cognition experiments typically need the rat to move through a stationary environment to indicate its understanding or memory of the space.