Consisting of a series of bunkers, the Maginot Line was built from 1930 onward between Alsace-Lorraine and the Saarland, and was intended to protect the French Republic.
Government of the United Kingdom, The Maginot Line, graphic, no date [before 1962]; image source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Maginot_Linie_Karte.jpg?uselang=de. Creative Commons Attribution ShareAlike 3.0 Germany.