The Atlantic Wall (German: Atlantikwall) was an extensive system of coastal fortifications built by Nazi Germany between 1942 and 1944 along the western coast of Europe as a defense against an anticipated Allied invasion of the mainland continent from Great Britain.

On March 23, 1942 Führer Directive Number 40 called for the official creation of the Atlantic Wall. After the St. Nazaire Raid, on April 13, 1942 Adolf Hitler ordered naval and submarine bases to be heavily defended. Fortifications remained concentrated around ports until late in 1943 when defences were increased in other areas.

Organisation Todt, which had designed the Siegfried Line (Westwall) along the Franco-German border, was the chief engineering group responsible for the design and construction of the wall's major fortifications. Thousands of forced laborers were impressed to construct these permanent fortifications along the Dutch, Belgian and French coasts facing the English Channel.

Early in 1944, Field Marshal Erwin Rommel was assigned to improve the Wall's defences. Rommel believed the existing coastal fortifications were entirely inadequate and he immediately began strengthening them. Under his direction, a string of reinforced concrete pillboxes was built along the beaches, or sometimes slightly inland, to house machine guns, antitank guns and light artillery. Mines and antitank obstacles were planted on the beaches themselves and underwater obstacles and mines were placed in waters just off shore. The intent was to destroy the Allied landing craft before they could unload.