Reyner Banham’s long-unavailable 1976 book has been reprinted, with an incisive new foreword by Banham historian Todd Gannon. It is especially welcome at a moment when the urban-planning and utopian projects of the late 1960s and ’70s are increasingly under critical review, assessed as monumental failures subject to demolition or as aesthetic exemplars of their age demanding preservation. A brilliant historical survey, conducted during the height of the short-lived movement and by a central player in the western architectural world of the time, the text provides insight into the aims behind what was called the “megastructural” movement, and useful categorizations of its different manifestations. First defined by the Japanese Metabolist Fumihiko Maki, in 1964, following the spate of projects for rebuilding that emerged from Kenzo Tange’s Tokyo office in 1960, the concept of megastructure as “a large frame in which all the functions of a city or part of a city are housed” soon took hold. It was a way for architects to respond to the demands of infrastructure, monumental form, and mass production integrated at a scale that went beyond the Modern Movement’s urban-zoning principles, to create buildings that were miniature cities and city developments conceived as single buildings.