The contemporary archaeology of urban mega-events. This book explores the traces of London’s most significant modern mega events the Great Exhibition of 1851, the 1951 Festival of Britain’s South Bank Exhibition, and the 2012 Olympic and Paralympic Games. Though only open for a few weeks or months, mega events permanently and disruptively reshape their host cities and societies: they demolish and rebuild whole districts, they draw in materials and participants from around the globe, and their organizers self-consciously seek to leave a legacy that will endure for decades or more. The book argues that these spectacles must thus be seen as long-lived and persistent, rather than simply transient or short-term phenomena. It explores the long-term history of each event through contemporary archaeology, examining the contents and building materials of the Great Exhibition’s Crystal Palace and their extraordinary afterlife at Sydenham, South London; how the Festival of Britain’s South Bank Exhibition employed displays of ancient history to construct a new postwar British identity; and how London 2012 dealt with competing visions of the past as archaeology, waste, and heritage in creating a vision of the future.