Duisburg is located in the German Ruhr area, called North Rhine Westphalia. Nearby cities include: Dortmund, Dusseldorf and Cologne, which can all be reached by train in a short time.
From Duisburg by train to:
Train to Hamburg from southern Germany stop at 3 railways stations in Hamburg. First Central Station, then Dammthor and the terminus is Altona. HH means Hansestadt Hamburg. HH Altona is not only the last railway station in Hamburg but also the last station for all train going between the major cities in Southern Germany to the Northern part of the country.
At least every hour there's a train to major cities in Germany: Dortmund, Dusselorf, Cologne (in 4 hours) , Frankfurt, Munich.