Built under the code name Kraftwerk Nord West (KNW) or in English - Power-plant Northwest this bunker  was to be one of the first to be built by the Germans. Work started in early March 1943, it was to be used for the reception, storage and the preparation for launching A4/V2 rockets. It was situated near the  the woods at Eperlecques; however, the Germans called it the Watten Bunker due to its short distance from the local train station. Within the north side of the bunker was another railroad station connecting this from the west via an underground and heavy protected tunnel was a spur line to the main Calais-St. Omer railroad line.

The original plan called for the bunker to be completed by 31st December 1943, so rocket attacks could be started against London by early 1944. Designed to house a liquid oxygen factory, the bunker could also house over 200 soldiers and its dimensions was in the region of 92m wide and 28m high. The roof was 5m thick and had a weight of 37,000 tons.

The proposal was to transport the rockets to the bunker on specialised trains, each train would carry 20 rockets, and 20 warheads. Once inside the bunker the rockets would be erected,  the warheads would be fitted and then the rockets would be fuelled before being placed onto a rail mounted launch pad. Once armed and fuelled, the rocket was to be moved through two armoured doors on the south of the bunker to the launch area. The control tower was located on the side of the building. The vision was to fire 30+ rockets each day.

On the left is one of the early aerial reconnaissance images of the site.

Flown by 541 Sqn on the 14th July 1943

The drawing shows an overhead view of the bunker site, showing what it would have looked like if it had been allowed to be fully completed by the Allies.

The red area, is the only part of the complex that was completed.