Photograph of barbed wire.
From an album of 26 photographs, showing scenes from World War One, Western Front (1914-1918), 1917-1918.

Thick belts of impenetrable barbed wire were placed in front of the front-line trenches on the Western Front. They were placed far enough from the trenches to prevent the enemy from approaching close enough to throw grenades in. Sometimes barbed-wire entanglements were designed to channel attacking infantry into machine-gun and artillery fields of fire.