What is "hartmannswillerkopf"

Hartmannswillerkopf, also known as the Vieil Armand or Hartmannsweiler Kopf (Hartmansweiler Head) is a pyramidal rocky spur in the Vosges mountains of Alsace. The peak stands at overlooking the Rhine valley. At Hartmannswillerkopf stands a national monument of World War I for the fighting which took place in the trenches here.