Can art or architecture change the world? Is it possible, despite successive failures, to think of a new cultural avant-garde today? What would this mean? Urban Avant-Gardes attempts to contribute to debate on these questions, by looking back to past avant-gardes from the nineteenth and twentieth centuries, by examining the theoretical and critical terrain around avant-garde cultural interventions, and by profiling a range of contemporary cases of radical cultural practices. The first section spans the late 19th to the mid 20th centuries, exploring the avant-gardes of Realism, early twentieth-century art and the architectural avant-garde of Modernism. Section two examines the period which stretches from the build-up to the events of 1968 to 1993, focusing particularly on the landmarks of the fall of the Berlin Wall, and opening of the Holocaust Memorial Museum in Washington DC. The third section begins in 1998 and asks whether there is a possibility for a new, perhaps 'green' avant-garde today; and whether - if there is - this might suggest a new attitude to, and construction of, a public sphere. Urban Avant-Gardes brings together material from a wide range of disciplin to argue for cultural intervention as a means to radical change, while recognizing that most such efforts in the past have not delivered the dreams of their perpetrators.