The ossuary is a memorial containing the remains of soldiers who died on the battlefield. Through small windows, the remains of 130,000 unidentified French and German soldiers can actually be seen filling small, windowed alcoves around the edge of the building. Inside, the ceiling and walls are covered by some of the names of soldiers who fell in the battle of Verdun. Some of the names are from the fighting in the area in WWII. The families of the individual soldiers recognized here paid for their plaques. In front of the monument lies the largest cemetery of France outside Paris with 15,000 graves. The ossuary was officially inaugurated on 7 August 1932 by French President Albert Lebrun.
From Wikipedia, see en.wikipedia.org/wiki/Douaumont_ossuary