A German officer and a soldier at the entrance of an underground shelter opening in the wall of a trench at Hartmannswillerkopf (Vieil Armand in French) near Mulhouse in spring 1916. As written on the sign, this "Fuchsbau " (burrow) had 2 exits and could accommodate 22 men (France, World War I). Photograph: Hans Hildenbrand - collection Noëlle and Jean-Noël Deletang.