It's a great green oasis in the otherwise somewhat grey city of Duisburg. And you get to see how…read morethe mines used to look like. Plus, there is Ruhrtriennale here every summer!

If you are interested in coke/steel production, then make the effort to visit. Here you get the…read morechance to climb all three of the furnaces. Much of the coke/steel production facility still remains; so much fascinating beauty among industrial decay. Nothing like this can be visited in the US; this is a worthy reminder of the Ruhrgebiet's history