Le Blockhaus d’Éperlecques, near St Omer, is a massive concrete structure intended as a launching point for rocket missiles directed at the United Kingdom during the Second World War. It was constructed from March 1943 as the V2 rocket was being developed at Peenemunde, and carried the code name Kraftwerk (power station) Nord West. The base was built by 35,000 slave labourers under the direction of Organisation Todt. The launching site, near the railway from Calais to St Omer, was intended to incorporate a factory for liquid oxygen, used as rocket fuel, and a bombproof railway tunnel linking underground missile stores with the launching ramp. The installation was designed to hold 100 missiles and to launch 26 a day. The significance of the site was recognised by the Allied forces in England as early as 16 May 1943 after aerial photographs were taken of it. The concrete installations were severely damaged by bombs dropped by the US air force on 27 August 1943. The RAF attacked the site with Tallboy bombs on 19 June and 25 July 1944, and it was captured by Canadian troops in the following September. Bombing prevented the use of the blockhouse for launching missiles - most of the V2s aimed at the United Kingdom were despatched from mobile Meillerwagen.
The retreating German troops turned off pumps which led to the flooding of large parts of the site. The Allied invasion forces were uncertain of the true purposes of the blockhouses, but used it from February 1945 for testing bombs. A museum was opened to the public as a private venture in 1973. The site was designated an historical monument in 1985. Visitors are able to see the launching ramp, the power station and examples of the tracked vehicles on which missiles were to be moved, the railway wagons that brought in supplies and the anti-aircraft guns that protected the site. Above all they are able to appreciate the vast scale of the concrete installations on the site.