The restoration of the Cheonggyecheon River that runs through Seoul, Korea, in a mere twenty-nine months—transitioning from an outmoded highway into a multipurpose performative infrastructure piece of unprecedented size—merits recognition as a seminal project in contemporary urban design. This remarkable achievement recovers the biological and social ecology of the city and demonstrates the profound ability of design at the urban scale to provoke positive transformation effectively over large territories. The project also signifies a broader sea change in Asian attitudes toward city design, from a quantitative model concerned primarily with growth to a more qualitative program that incorporates quality of life and environmental sustainability into strategies for economic development. In this well-illustrated volume, contributors consider the ecological, infrastructural, and urban impacts of this exceptional project at the heart of the city. For its many merits, the Cheonggyecheon restoration was awarded the Tenth Veronica Rudge Green Prize in Urban Design by the Harvard Graduate School of Design.