Built in 1885 and reinforced several times up to 1913, Douaumont fort was covered with a concrete shell and several metres of sand. This strategical observatory was taken by the Germans at the beginning of the Battle of Verdun, then re-taken by French eight months later. Galleries, casemates and arsenals show that the fort was an important stronghold. A chapel marks the site of a walled-up gallery where 679 German soldiers, killed in the accidental explosion of an ammunitions store, were buried on 8 May 1916.