The Blockhaus d'Éperlecques is a Second World War bunker, now part of a museum, only some 14.4 kilometers north-northwest from the more developed La Coupole V-2 launch facility, in the same general area.
The bunker, built by Nazi Germany under the codename Kraftwerk Nord West (Powerplant Northwest) between March 1943 and July 1944, was originally intended to be a launching facility for the V-2 (A-4) ballistic missile. It was designed to accommodate over 100 missiles at a time and to launch up to 36 daily.
The facility would have incorporated a liquid oxygen factory and a bomb-proof train station to allow missiles and supplies to be delivered from production facilities in Germany. It was constructed using the labour of thousands of prisoners of war and forcibly conscripted workers used as slave labourers.
The bunker was never completed as a result of the repeated bombing by the British and United States air forces as part of Operation Crossbow against the German V-weapons programme. The attacks caused substantial damage and rendered the bunker unusable for its original purpose. Part of the bunker was subsequently completed for use as a liquid oxygen factory. It was captured by Allied forces at the start of September 1944, though its true purpose was not discovered by the Allies until after the war. V-2s were instead launched from Meillerwagen-based mobile batteries which were far less vulnerable to aerial attacks.
Today, the bunker is preserved as part of a privately owned museum that presents the history of the site and the German V-weapons programme.
References:The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.