We are driving from Düsseldorf to Siegen in a few days to get our son settled into his apartment at the university. We'll have a day or so to explore the area. Any hot tips for things to do in the area?
Siegen is downright ugly. The region is not, but exploring without a car would be inconvenient. So I think the best you can do is a day trip either to Köln or to the nice historic town of Marburg. There are direct trains to Köln (and you could use a NRW ticket, which is valid for urban transport in Köln too). Going to Marburg implies at least one transfer.