About 12 kilometers south of Dortmund on a wooded crag above the Ruhr valley, the Hohensyburg, or Syburg, is an ancient castle complex dating back to the 8th century.

 The castle ruins seen today date from around 1100 and include two large keeps, the former living quarters, and remnants of the old wall. A more recent addition is the war memorial, added in 1930 to commemorate the fallen from WWI. 

A popular destination for hikers, the hill also has a number of other attractions, including the Vincketurm, a 26-meter-high tower offering panoramic views, and the Kaiser-Wilhelm-Memorial, built in 1902.