Sitting high on a hill, this is the strongest of the 38 fortresses and bastions built along a 45km front to protect Verdun. When the Battle of Verdun began, 400m-long Douaumont – whose 3km network of cold, dripping galleries was built between 1885 and 1913 – had only a skeleton crew. By the fourth day it had been captured easily, a serious blow to French morale; four months later, it was retaken by colonial troops from Morocco.
Charles de Gaulle, then a young captain, was wounded and taken prisoner near here in 1916. It’s free to take in the sweeping country views from the fort’s crater-pocked roof.