Ephemeral Urbanism invites us to ponder material impermanence. Is a recognition of the transitory nature of physical substances integral to the city construction process? This book makes a convincing argument in the affirmative. A creation of the Ephemeral City Research Project - conceived at the Harvard Graduate School of Design, with the aim of making non-permanent configurations of the city landscape a legitimate addition to current urban discourse - this book features temporary settlements from all over the world that challenge the illusion of urban immutability. Ranging from inter-city infills to mega-scale metropolises, Ephemeral Urbanism overviews hundreds of case studies, analysing configurations that exist only for a limited period of time. Through diagrams, photographs and aerial images, this preliminary survey presents interesting prototypes of flexible urban planning and design. Accompanying texts by Richard Sennett and Ricky Burdett provide a framework for understanding the relevance of this book.