"This book will consider the visual quality of the American city by studying the mental image of that city which is held by its citizens. It will concentrate especially on one particular visual quality: the apparent clarity or "legibility" of the cityscape. By this we mean the ease with which its part can be recognized and can be organized into a coherent pattern. [...] This book will assert that legibility is crucial in the city setting, will analyze it in some detail, and will try to show how this concept might be used today in rebuilding our cities."
Just the first and fourth chapter of Kevin Lynch's "The Image of the City" (1960), one of the most relevant books regarding planning and urban design, as it introduced for the first time the idea of understanding the city not as an object in itself, but as a system perceived by its inhabitants. Unmissable reading even today...
Remember this picture of Frank Lloyd Wright at Taliesin? Kevin Lynch is the second sitting student from the left: http://designmuseum.org/__entry/4924?style=design_image_popup
Via Ignacio López Busón