Now that most of us live in cities our attention turns increasingly to how different these places are around the world and why this might be so. Are there underlying processes at work that influence or even determine the ways in which cities grow? To what extent are particular cities dependent on paths or foundations laid down centuries ago? To what extent can planners (using the term loosely) shape the way cities grow, how they look and how we experience them? Many have attempted to answer these questions, with varying degrees of success, and from a variety of perspectives