Hagen is a city in the state of North Rhine-Westphalia, Germany, on the southeastern edge of the Ruhr area, 15 km south of Dortmund, wher…Hagen is a city in the state of North Rhine-Westphalia, Germany, on the southeastern edge of the Ruhr area, 15 km south of Dortmund, where the rivers Lenne and Volme meet the Ruhr. In 2023, the population was 197,677.