Douaumont Ossuary

The Douaumont Ossuary is a memorial containing the skeletal remains of soldiers who died on the battlefield during the Battle of Verdun in World War I. It is located in Douaumont-Vaux, France, within the Verdun battlefield, and immediately next to the Fleury-devant-Douaumont National Necropolis. It was built on the initiative of Charles Ginisty, Bishop of Verdun.

Source: Wikipedia