A fundamental problem in the simulation of systems of discrete interacting entities is how to represent the environments they inhabit. However we think about it, if individuals move in space and social interaction takes place through meeting, space patterns that constrain movement may intervene in the construction of social behaviour. This chapter investigates the spatial patterns that human societies construct—the forms of their towns and cities—and argues that they are far more than just a background to, or expressions of, social action, but are instrumental in the formation and reproduction of patterns of social behaviour that make meaningful personal and social action possible.