Book excerpt: The term "psychogeography" is used to illustrate a bewildering array of ideas, from ley lines and the occult to urban walking and political radicalism—where does it come from and what exactly does it mean? Psychogeography is the point where psychology and geography meet in assessing the emotional and behavioral impact of urban space. The relationship between a city and its inhabitants is measured firstly through an imaginative and literary response, secondly on foot through walking the city. This creates a tradition of the writer as walker and has both a literary and a political component. This guide examines the origins of psychogeography in the Situationist Movement of the 1950s, exploring the theoretical background and its political applications as well as the work of early practitioners such as Guy Debord and Raoul Vaneigem. Elsewhere, psychogeographic ideas continue to find retrospective validation in much earlier traditions from the visionary writing of William Blake and Thomas De Quincey to the rise of the flâneur on the streets of 19th century Paris and on through the avant-garde experimentation of the Surrealists. These precursors are discussed here alongside their modern counterparts, for today these ideas hold greater currency than ever through the popularity of writers and filmmakers such as Iain Sinclair and Peter Ackroyd, Stewart Home and Patrick Keiller. This guide offers both an explanation and definition of the terms involved, an analysis of the key figures and their work, and practical information on psychogeographical groups and organizations.