Douaumont -- the Fort

Fort Douamount

http://en.wikipedia.org/wiki/Douaumont

Verdun was the strongest point in pre-war France, ringed by a string of powerful forts, includingDouaumont and Vaux. By 1916, the salient at Verdun jutted into the German lines and lay vulnerable to attack from three sides. The historic city of Verdun had been a Gallic fortress before Roman times and later a key asset in wars against Prussia, and Falkenhayn suspected that the French would throw as many men as necessary into its defense.