At the approaches to the Citadel of Belfort there are signs pointing to the Grand Souterrain (large underground). At first I thought this was a tunnel of some sort, but it turned out to be a maze of subterranean spaces under and behind the Citadel.
The city’s website explains that the Grand Souterrain was started in the Middle Ages as an open trench behind the Citadel, like the dry moat of a medieval castle. Vauban covered it with a roof in the 17th century, to protect it from cannonballs and artillery shells.
In the 19th century, General Haxo transformed and enlarged it using stone walls and earthworks, creating an underground space where 1000 to 1200 men could take shelter, along with a mezzanine for the storage of ammunition and food.
A lower level allowed access to numerous casemates, i.e. narrow openings where artillery could be fired against attackers. These accesses still exist but are not open to the public.
It is possible, however, to walk through part of the Grand Souterrain, the part where Colonel Denfert-Rochereau and his men held out for 103 days during the siege of 1870-71.
Since this was just a dark space with nothing to see, the city has now equipped it with projectors illustrating the history of the citadel and the city. Visitors now get audio guides with explanations in various languages.
The walk through the Grand Souterrain leads uphill, and when you get to the end you find yourself unexpectedly, after your eyes get accustomed to the light, in the newly renovated café and restaurant at the top of the citadel.
From the restaurant it’s just a few more steps up to the Panoramic Terrace, with views in all directions.
Location and aerial view on monumentum.fr.
My photos in this post are from 2016. I wrote the text in 2020.
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