The Ruhr has experienced the same structural difficulties faced by similar “rust belt” regions elsewhere, but it has risen to the challenge of re-using its redundant industrial sites in a very different way. Instead of bulldozing them, many have been preserved in acknowledgement of the historical significance and tourist potential of these so-called “cathedrals of industry”. Today, a 400km road route and a well-signposted 700km cycle trail form the Route der Industriekultur (Industrial Heritage Trail; route-industriekultur.de) link former steelworks, coal mines and slagheaps to offer a fascinating insight into the technology of heavy industry, with a healthy injection of contemporary culture. Some of the most significant attractions are dealt with in the individual city sections here, but others are listed here. You can rent bikes for €1 per hour from one of the 300 cycle stations scattered across the region – you just have to register free first (metropolradruhr.de).