Along the way are Gallo-Roman grain silos, dungeons in the mediaeval belfry, and the highlight, a magnificent succession of illuminated archways, leading off as far as you can see. A magnificent underground cathedral. “It’s a line of fire between two of the citadel bulwarks. Behind each arch was a casemate where soldiers were stationed, ready to defend their fortress.”
After passing through the powder magazine, the tunnel leads up to the top of the citadel. The view is breath-taking. Situated on the top of a hill, the cathedral overlooks the whole surrounding area. In the distance you can make out the ridge between the Ailette valley, the Aisne valley and the Chemin des Dames, a critical location for the First World War.