Our decisions shape our future, but we know little about how. To find out, planners and designers construct vivid images of what could be. These scenarios serve as path-breakers between imagination and reason. In the late 1980s, the elite of Dutch planning and design took scenarios to unprecedented scales to convince the public of their ideas. But the quest to reshape the Netherlands as a whole failed dismally. Their attempt, however, unleashed a wave of new thinking about the future and created an enormous number of spectacular images of things to come. Dutch New Worlds tells for the first time the story of how scenario thinking changed urbanism and physical planning, from its beginning in the late 1960s to its height in the 1990s. It shows how most grand scenario projects came to nothing because of overambition and misuse. It also shows how, today, scenarios remain powerful tools for focused and transparent design research to create better cities and regions. Told from the perspective of an architect and urbanist, this history of ideas holds fundamental lessons for planners, designers, and policy makers - and for our next decisions that will shape our future.