In the twenty-first century, the Ruhr areawith 5.1 million inhabitants, the largest conurbation in Germanyfinds itself poised between historical preservation and modernization: the region still stands for its mining past and its postindustrial transformation, and yet it also offers an example of sustainable urban and regional development. The more the structural change of the region advances, the more the Ruhr area reflects a pattern common to many cities internationally: the in-between urban spaces become more connected to the densely populated centers that are traditionally found in European cities. This book is being published on the occasion of the 100th anniversary of the Siedlungsverband Ruhrkohlenbezirk, now the Regionalverband Ruhr. This organization was founded in 1920, at the beginning of the Weimar Republic, as a planning and environmental body and is today still the largest metro administrative body in Europe. The volume offers a programmatic agenda for the future. It documents the history, strategy, and governance of the Regionalverband Ruhr as a network organization for regional management that has jointly been responsible for internationally renowned lead projects such as the IBA Emscher Park, RUHR.2010European Capital of Culture, Ruhrtriennale, Green Infrastructure, and the IGA Metropole Ruhr 2027. Using texts, images, and plans, it vividly depicts the inner master plan for the Ruhr metropolis, producing a master narrative not least of all for the areas of soft regionalization, culture, tourism, industrial culture, and economic and scientific marketing in the city of cities.