Related Clues:
- German industrial valley
- Bad ___ (Lower Saxony city)
- Essen's region
- Remscheid's region
- City of the Ruhr valley
- City near Düsseldorf
- It's near Gelsenkirchen
- Krupp steel hub
- Chief city of the Ruhr River valley
- Ruhr region
- Industrial city in Germany
- City near Oberhausen
- City in the Ruhr valley
- Where Wuppertal is
- German iron and steel center