Fort Schoenenburg is an underground shelter built after World War I to protect France against aggressors from the east. It is part of the Maginot Line, a series of similar installations where soldiers should effectively resist enemy combatants. Huge efforts and spending were in vain. Based on experiences and lessons learnt in the first World War in the 20th century this defense strategy did not work at all with the new way of war with tanks and airplanes. While hundreds of soldiers where lurking underground, the enemy rushed across the borders and took the country within short time. 

However this monument is an impressive remain of those violent times from the previous century.