Fortress of Mimoyecques

Fortress of Mimoyecques Wiese Bauvorhaben 711 Marquise-Mimoyecques
Mimoyecques, near Landrethun-le-Nord (France)
Reconstructed view of the installation as originally planned
Fortress of Mimoyecques
Coordinates	50°51′14″N 1°45′32″E / 50.854°N 1.759°E / 50.854; 1.759
Type	Bunker
Site information
Owner	Conservatoire d'espaces naturels du Nord et du Pas-de-Calais
Open to the public	Yes
Website	mimoyecques.fr
Site history
Built	September 1943 – July 1944
Built by	Organisation Todt
In use	Never completed, captured 1944
Materials	150,000 cubic metres concrete
Battles/wars	Operation Crossbow
Events	Critically damaged 6 July 1944; Captured 5 September 1944; Opened as museum 1984, reopened 1 July 2010
Garrison information
Garrison	Abteilung 705 (English: firing detachment 705) [1]

The Fortress of Mimoyecques (French pronunciation: [mimɔjɛk]) is the modern name for a Second World War underground military complex built by the forces of Nazi Germany between 1943 and 1944. It was intended to house a battery of fixed V-3 cannons permanently aimed at London, 165 kilometres (103 mi) away. Originally codenamed Wiese ("Meadow") or Bauvorhaben 711 ("Construction Project 711"),^[2] it is located in the commune of Landrethun-le-Nord in the Pas-de-Calais region of northern France, near the hamlet of Mimoyecques about 20 kilometres (12 mi) from Boulogne-sur-Mer. It was constructed by a mostly German workforce recruited from major engineering and mining concerns, augmented by prisoner-of-war slave labour.

The complex consists of a network of tunnels dug under a chalk hill, linked to five inclined shafts in which 25 V-3 guns would have been installed, all aimed at London. The guns would have been able to fire ten dart-like explosive projectiles a minute – 600 rounds every hour – into the British capital, which Winston Churchill later commented would have constituted "the most devastating attack of all".^[3] The Allies knew nothing about the V-3 but identified the site as a possible launching base for V-2 ballistic missiles, based on reconnaissance photographs and fragmentary intelligence from French sources.

Mimoyecques was targeted for intensive bombardment by the Allied air forces from late 1943 onwards. Construction work was seriously disrupted, forcing the Germans to abandon work on part of the complex. The rest was partly destroyed on 6 July 1944 by No. 617 Squadron RAF, who used ground-penetrating 5,400-kilogram (12,000 lb) "Tallboy" earthquake bombs to collapse tunnels and shafts. This also entombed hundreds of slave workers underground. Though attempts were made to continue construction, the Germans soon halted work at Mimoyecques entirely as the Allies advanced up the coast following the Normandy landings. It fell to the Canadian 3rd Infantry Division on 5 September 1944 without resistance, a few days after the Germans withdrew from the area.^[4]

The complex was partly demolished just after the war on Churchill's direct orders (and to the great annoyance of the French, who were not consulted), as it was still seen as a threat to the United Kingdom. It was later reopened by private owners, first in 1969 to serve as a mushroom farm and subsequently as a museum in 1984. A nature conservation organisation acquired the Fortress of Mimoyecques in 2010, and La Coupole, a museum near Saint-Omer housing a former V-2 rocket base, took over its management. It continues to be open to the public as a vast underground museum complex.^[5]