This paper seeks to contribute to the project on the Impact of the Ancient City by offering some thoughts on the contribution of archaeology to the understanding of ancient town planning. Issues concerning the later reception of ideas of the Classical town planning are entangled with perceived understandings of ancient planning, and these in turn are a product of the evidence itself and how it has been understood. As explored in other contributions, such perceptions are varied and have been influenced by scholars’ presumptions as well as their reading of different strands of the ancient evidence. My contribution has little to add these already nuanced debates. Instead, it seeks to explore two related themes. First, how (sometimes rather simplistic) past perceptions have influenced the construction of the archaeological evidence on which historians, geographers and town planners have then relied. Second, how new methods can provide a better evidence base which might enable us to understand the principles of Roman town planning rather better. In considering some results from such work, I also want to argue for a more three-dimensional viewing of town plans. In this discussion, I will draw on evidence from both Italy and Britain, with particular reference to sites at which I have undertaken archaeological work: I hope that this does not appear too self-referential.