Located in the Pays de la Loire region around 28km northeast of the busy port and U-Boat bunker site at Saint Nazaire, the small town of Pontchateau was an important railway node in western France.
Owing to its location and transport links to Nantes, Vannes, and Brest, following the occupation of the area in June 1940 German forces began excavating a series of tunnels at a former quarry site to the north of the town.
The site was to be used by the Kriegsmarine to assemble and store magnetic sea mines inside a series of interconnecting underground galleries and linked tunnels.
However, the work was never completed to the extent planned and the site was handed to the German Army who bolstered the excavations with a large concrete shelter to house one of four captured 24cm French modele 93/96 TAZ coastal defence/railway guns which were pressed into service in the Saint Nazaire area.
Linked to the rail network, the 19.5m long gun based here was transported to three firing positions in the local area – one at Besne to the south, Campbon to the east, and Savenay to the south east.
It’s just outside the railway station at Savenay where the gun was captured by advancing Allied troops on May 11, 1945. It’s believed that this gun was the last of its kind to fire during the war.
Today the Pontchateau site is very difficult to find and even when you stand in the large car park in front of the shelter entrance. You’d be forgiven for missing the concrete building such is the level of vegetation covering it.
However, the shelter itself can be accessed with extreme care at the edge of the old quarry face, although it’s not advised to explore the tunnel system behind it due to rockfalls dangerous drops.
Unlike the Dombunkers of northern France, this protective shelter also featured defensive machine gun positions built into its structure. The whole site features some extensive graffiti too, with some in places you wouldn't think possible of reaching!