There's no getting around it anymore. We are in an age of globalization, and cities around the world are being challenged in brand new ways with no historical precedents to guide them. The highly anticipated international building exhibition IBA Hamburg 2013 is preparing to tackle the many challenges that apply to metropolises around the world in our era, asking difficult questions and soliciting innovative responses. Socially and geographically, how can we bring peripheral districts back into the city? How can we tap the full potential of international urban society? How can we cope with the requirements of climate change? This first installment of a ten-volume series leading up to the 2013 conference features retrospective documentation of former German building exhibitions, an outlook to the IBA Hamburg and complex considerations of the metropolis phenomenon.