The Forteresse de Mimoyecques exists as a frightening example of the Führer’s ambition.

Hidden underground in the Northern French hamlet of Landrethun-le-Nord lurked a very grim threat intended to aim directly into the heart of the British capital. A subterranean bunker with a series of tunnels that connected to five shafts that inclined upwards, this secret complex was to be the placeholder for 25 new, experimental weapons that would all be pointing straight at London. 

The V3 was a massive super gun, designed to be capable of firing explosive projectiles at the rate of 600 rounds per hour. The V3, codenamed Hochdruckpumpe (High Pressure Pump) was developed by Reich Minister of Armaments and War Production Albert Speer, and regardless of its prototype status, absolutely delighted Hitler. Giving the weapon’s development and employment his full support despite the absence of any firing trials, the Führer also had to consider the type of engineering base such a weapon would need to be consistently fired for any amount of time.

The solution presented itself as an underground launching base, supported by the already existing railroad. Ammunition storage galleries, five drifts capable of clustering 5 V3’s each, and a network of tunnels were installed once the hill was excavated, built by over 5,000 German workers as well as hundreds of miners and Soviet prisoners. Construction began in September 1943 and had a target date of March 1944, but relentless bombing from the Allies thwarted the deadline. French agents had an inkling that something was afoot in the hill by late 1943, but without the proper intelligence, they couldn’t get close enough to the site to uncover the goings-on, and the Germans went on diligently building.

However, the ambitious undertaking that could have easily devastated London wasn’t meant to be. The high-reaching project couldn’t withstand the relentless shelling, and when Mimoyecques became the focus of the Allied air forces, the site was so bombarded that the Germans were forced to desert what they were sure would be their game-changing advantage. By July, 1944, the tunnels had been collapsed and and the majority of the bunker was destroyed. 

After several attempts by the British to safely demolish the substantially solid bunker (thoroughly pissing off the French who were not invited to discuss the site’s fate) the complex was finally closed off through demolition. Private owners eventually reopened the tunnels as a museum in 1984 by gaining access through one of the five drifts that was meant to hold the super guns. The museum serves as a memorial as well as a sanctuary to a large colony of rare bats.