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Führer Directive No. 40 -

On March 23, 1942, Adolf Hitler issued Führer Directive No. 40, his order for the construction of an extensive system of coastal defenses and fortifications known as the Atlantic Wall. The Nazi leader is seen with Albert Speer, Minister of Armaments and War Production, and Karl-Otto Saur, head of the technical department.

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Building on previous foundations -

The coast of northern France was already well defended by the Germans. In this 1941 image, the entrance to Calais is protected by German DCA anti-aircraft guns. In fact, the work which constituted the frame of the Atlantic Wall was laid over elements of the offensive system built for the proposed invasion of England.

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Organisation Todt -

But a more robust defense was needed. The idea was to fortify Europe's northern shore with a long chain of fortresses, batteries, gun emplacements, tank traps, and obstacles. Work started immediately, the ambitious project overseen by the Organisation Todt (OT).

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Construction of the Atlantic Wall -

The OT was notorious for using forced labor to undertake and complete its civil and military engineering initiatives. The Atlantic Wall was no different. An estimated 600,000 men were drafted in by the pro-Nazi Vichy regime in France to build the installations.

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Massive engineering project -

The plan called for the construction of 15,000 separate concrete emplacements, a three-tier system of fortifications that was supposed to run from the France-Spanish border all the way to the northern tip of Norway—a distance of almost 3,218 km (2,000 mi).

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Defensive strategy -

The most heavily defended fortifications were concentrated around strategic port cities such as  Cherbourg, Le Havre, and Antwerp. Pictured checking building progress is Admiral Hermann von Fischel, Albert Speer, and SS commander Sepp Dietrich.

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The wall reaches the Channel Islands -

The Channel Islands were already under German occupation, having been invaded in June 1940. The Atlantic Wall was extended to heavily fortify the islands and in particular, Alderney—which is closest to Britain.

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Defending the Dutch coast -

In Holland, concrete tank obstacles were laid across beaches to strengthen defenses along the Dutch coast.

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High security in the lowlands -

The lowlands, including Denmark, were defended by system of interconnected bunkers and medium caliber guns.

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Fortress Norway -

Norway was heavily defended by the Nazis and in fact was known as Festung Norwegen ("Fortress Norway"). As with France, the defensive wall here was laid in areas where the Germans considered an Allied attack most probable. It effectively marked the Northern Front.

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Coastal defense network -

Elements of the wall's operation were overseen by the Kriegsmarine (German navy), which maintained a a separate coastal defense network, organized into a number of sea defense zones. Pictured is Admiral Otto Ciliax inspecting the Atlantic Wall in Norway.

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Concrete city -

Hitler wanted the work completed by May 1, 1943. This ultimately proved impossible as the war started to turn in the Allies' favor and raw materials and manpower dwindled. But what had already been built along the coast of northern France provided a formidable obstacle to any invasion by sea. In places installations resembled a city plan, with wide runways leading past huge bunker buildings, where personnel numbering in their thousands lived and worked.

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Batterie Todt -

Several gun emplacements were colossal in their dimensions. One of the most famous was the Batterie Todt. Located near Cap Gris-Nez, the battery consisted of four gargantuan Krupp 380-mm (15 in) guns with a range up to 55.7 km (34.6 mi) and capable of striking England.

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Life in a bunker -

Life for combatants deployed to the Atlantic Wall was routine and claustrophobic. Much of the time was spent checking and maintaining equipment. In this photograph, Wehrmacht personnel in a bunker in Heligoland practice loading a shell into the barrel of gun.

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Stockpiling munitions -

A soldier checks shells stored in the munitions stockpile in a gun bunker. The most heavily defended installations were called festungen, or "fortresses."

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Relaxing off duty -

Off-duty, gun emplacement personnel had little to do other than read, catch up on correspondence, or sleep.

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Medical facilities -

Principal gun emplacements featured fully-equipped hospital bunkers. These were staffed by medical teams ready to treat wounded soldiers or deal with everyday disorders, such as an appendectomy.

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Railway guns -

Above ground, rail tracks served the Atlantic Wall to facilitate the transportation and maneuver of huge railway guns, which could be deployed quickly in case of attack.

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Anti-aircraft installations -

Besides bristling with weaponry, the Atlantic Wall was armed with ground equipment designed to detect Allied aircraft flying under the radar long before they attacked. These were anti-aircraft unit sound detectors, ingenious listening devices that were sensitive enough to detect the sounds of approaching aircraft at an impressive range. They were invariably positioned next to powerful searchlights.

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Posing for propaganda -

The French Channel coast was deemed by the German high command as impregnable to attack. Nazi propaganda images were frequently published showing machine gunners stationed on the Atlantic Wall, their weapons primed and ready.

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Coastal patrols -

France's wilder northern coastline was regularly patrolled by units of the Wehrmacht. These soldiers would check areas out of sight of gun emplacements and likely favored by Allied forces as covert landing zones.

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Reconnaissance work -

Germany's Atlantic defenses provided lofty platforms for reconnaissance units tasked with keeping an eye out across the English Channel for Allied aircraft and naval movements. State-of-the-art telephoto lenses aimed at England provided detailed photographs of tactical and geographical relevance.

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Razor-sharp obstacle -

Approaches to pillboxes and blockhouses were defended by razor-sharp barbed wire, often double fenced to serve as a menacing deterrent.

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On the beaches -

Beaches, meanwhile, were littered with tank traps, mines, and landing craft obstacles, and were regularly patrolled, day and night, by units of German guards.

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Rommel's concerns -

Throughout most of 1942–43, the Atlantic Wall remained a relaxed front for the Axis troops manning it. But an inspection by Field Marshal Erwin Rommel in late 1943 undertaken after Allied invasion rumors reached Berlin resulted in efforts to strengthen the line. In fact, Rommel was highly skeptical of the Atlantic Wall's ability to suppress a full-scale invasion. And events proved him right.

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The Atlantic Wall is holed -

On June 6, 1944—D-Day—Allied troops punched a hole through the Atlantic Wall, albeit at a cost to thousands of lives on both sides. In mere hours the Allies had secured five beachheads along the Normandy coastline. Hitler's much vaunted line of concrete bunkers and emplacements had failed to stop the Normandy landings.

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Ruins of the Atlantic Wall -

In the immediate aftermath of the Second World War, there was scant interest in preserving the wall, its presence stirring up too many negative memories of Nazi occupation. In time, many of the abandoned fortifications were demolished. Others, however, survived to become official historical monuments, such as the Longues-sur-Mer artillery battery (pictured)⁠—the only one in Normandy to retain all its original guns in situ⁠.

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Silent guns -

In Norway, several decommissioned gun emplacements stand as testimony to the wall's presence in Scandinavia. The one pictured is located on the coast near the fishing village of Bud.

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Batterie Todt -

Back in northern France, the iconic and disarmed Batterie Todt in the Pas-de-Calais département is still visible and accessible to the public.

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Crisbecq Battery -

The ruins of the Crisbecq Battery near the village of Saint-Marcouf also impress visitors, empty gun emplacements and all.

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Museum of the Atlantic Wall -

Known also as the "Grande Bunker," the highly engaging Museum of the Atlantic Wall offers a fascinating glimpse into the history behind one of the costliest, most ambitious, but ultimately flawed wartime engineering projects. It's housed in an original blockhouse and located at Ouistreham in Normandy.

Sources: (Military History Now) (Britannica) (Liberation Route Europe)

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