Hartmannswillerkopf, also known as the Vieil Armand or Hartmannsweilerkopf is a pyramidal rocky spur in the Vosges mountains of Alsace. The peak stands at 956 metres (3,136 ft) overlooking the Rhine valley. At Hartmannswillerkopf stands a national monument of World War I for the fighting which took place in the trenches here.
The peak is located 9 kilometres (5.6 mi) from Cernay and 24 kilometres (15 mi) north of Mulhouse. The mountain is shared by the towns of Hartmannswiller, Wuenheim, Wattwiller and Uffholtz and has been a strategic area bitterly fought for. The most severe fighting for the peak took place on 19-20 January, 26 March, 25-26 April and 21-22 December 1915. Through the course of the war, thirty thousand deaths were reported with a majority of these among the French. After about 18 months of fierce combat, both sides began to focus most of their attentions on the western front farther north. Only enough men to hold the lines were left at Hartmannswillerkopf, and they remained relatively stable for the remainder of the war and generally only artillery exchanges took place.
Today, the area is a French national monument. There is a museum and a cemetery at the site, and it is also possible to explore the extensive trench system. Because the lines were static for such a long period, the trenches are very well preserved, especially on the German side of the mountain. As of 2011[update], restoration work ahead of the centenary of the war means that access to the memorial is restricted.
There is a small memorial on the D431 north of Vieil Armand, commemmorating Halifax bomber MZ807 of No. 433 Squadron RCAF, which crashed nearby in December 1944.