Duisburg, Germany

Straddling the Rhine at the point where the Ruhr empties into it, DUISBURG is the western gateway to the Ruhrgebiet and, with a population of half a million, its third largest city. Though the surviving medieval defences point to a long history, it was the industrialization of the Ruhr in the nineteenth century that transformed it into a major city, the largest inland port in Europe as well as a centre for steel, coal and engineering. From the mid-1960s onwards, Duisburg's heavy industries went into decline, but the city has faced its challenges with drive and imagination, restructuring its economy towards technology and services and hiring the British architect Norman Foster to oversee its physical transformation. These days its engrossing museums, reworked industrial landscapes and funky, revitalized docks are worth a day or two of anyone's time.