Duisburg, Germany

Duisburg sits at the confluence of the Rhine and Ruhr rivers in western Germany, with roughly 500,000 residents. The city operates the world's largest inland port, moving 12 million tonnes of cargo each year across 22 kilometres of dock. The 1990 Landschaftspark Duisburg-Nord turns the 1901 to 1985 Thyssen steelworks into a 200-hectare industrial landscape, while the medieval Old Town holds the 1000-year-old Salvatorkirche. The 1977 Lehmbruck Museum specialises in modern sculpture, and the 1973 Tiger and Turtle sculpture lets visitors walk a hilltop roller coaster.