The Butte de Vauquois is the highest hill in the area west of the Argonne, France and offers an unobstructed view in all directions. In September 1914 the Germans occupied this hill and made it a fortress. The French have attacked the position repeatedly with little success.

On March 4, 1915 the French Army attacked the Butte de Vauquois with thousands of men several times. Since they lacked the strategic advantage of topographic height, they suffered enormous casualties, only capturing the southern side of the hill by the end of the day. The top, with its ruined village, is a no-man’s land.

The French plan is to build mine tunnels through the dry and stable bedrock towards the German lines. Soldiers from coal-mining areas will be employed to dig caverns underneath the German trenches. Once this Mining War starts, no doubt the Germans will respond with tunnels of her own.

http://woostergeologists.scotblogs.wooster.edu/2010/08/16/battle-of-the-mines-vauquois-1915-1918/