Ruhr region, Germany

The Ruhr region is an urban area consisting of several large, formerly industrial, German cities, such as Essen and Duisburg, bordered by the Ruhr and Rhine rivers.

Rich in coal deposits, the Ruhr area started large-scale coal-mining and steel-producing in the first half of the 19th century, soon evolving to be world's most famous industrial area.

Its prosperity helped finance Nazi Germany during World War II. Later, oil-refining and petro-chemical industries thrived in the Ruhr area as oil consumption around the world surged.

But draining resources and growing competition took their toll. Since the 1960s, the Ruhr region has invested large sums in its transformation. Buildings and facilities were converted into museums and entertainment areas, preserving the history of the industrial age.