Haunting is what I felt at Verdun. It was like each of those crater is an open grave and many of them are today as men buried by shell blast have been exposed by time and weather.
I could not decide if I could feel them or was just feeling the scale of carnage. Think of miles of shell holes, miles fought for over and over again with no end of the war in sight. I understand why the French refused to attack at one point. Defend yes, attack no more. They were used up as a combat force and had not rotation system to get them back into shape as a fighting force.
Dunkirk was inspiring because you knew they got out and lived to fight another day. The D-Day invasion sites were sobering because you knew the cost to gain that foothold was steep and had been paid for by men in blood. But the trench warfare type of field works and the shell holes a hundred years later at Verdun was just haunting. There are areas of France still closed to humans because there is just too much un-exploded ordinance in and on the ground.
Sometimes going out of your way pays and sometimes it cost. I'd rather see it for myself. History, in books, does not give you a scale for events. Think about a system of trenches from Boston to DC with men fighting in them for years. Not all over, all the time but in spurts, in waves and in floods of men. Never mind the great battles with thousands killed in hours for no real gains.