Memorial to the 152 Reg. Chasseurs a Pied - ?Diables Rouges? / ?Red Devils? overlooking the Rhine valley. HWK (Hartmannswillerkopf) was also known to the French as ?Le Vieil Armand? is a 900m hill rocky spur with extensive views over the Rhine plain north of Mulhouse. Of obvious strategic significance it was heavily fought over for much of the war and has some of the most extensive German fortifications of any region of the Western Front.