The Douaumont Ossuary is the most affecting monument on the battlefield. The long concrete building, with its 46-metre tower in the shape of a sword-hilt rising from the centre, was built in the 1920s to gather the unidentifiable bones of soldiers — French and German alike — recovered from the surrounding fields. Through small windows along the outside, you can see those bones still: piled in chambers below the floor of the upper hall.
Inside, the long red-lit Hall of Names lists 12,000 French dead identified by their families. The 16,000-grave national cemetery spreads out below. The view from the tower over the cratered landscape is a reminder that the fields you are looking at are still, in places, churned by 1916 shellfire.