When you take a long walk in the Brasselsberg area at Kassel, Germany and move into the direction of the Hirzstein mountain you can find something special: the ‘Teufelsmauer‘ or devils wall. It is a natural formation made of basalt that looks like a wall that is 30 meters long, 10 meters high and 90 centimeters thick. But the devil has nothing to do with it: it was magma that flowed into a crack in more weak rocks.
Later at this place basaltic tuff was gained to build the Herkules monument and the ‘wall’ was found. Close-by you can find a protective hut for hikers called the ‘Teufelseck‘.