Fort Eben-Emael was built, most of it inside a hill, commencing in April 1932 as a part of Belgium’s defences against a second invasion (the country was occupied by Germany during World War I)
It was sited overlooking the Albert Canal, with big guns which could if necessary demolish the Kanne, Vroenhoven and Veldwezelt road bridges in case of invasion via Maastricht.With over 25 km of Dutch territory for the Germans to cross, it was thought there would be ample warning of an attack. Sadly, the fort was taken on 10 May 1940 by troops landing silently on the roof from gliders. lat roof so the soldiers could play football! Many of them were in barracks, outside the fort, when the attack came.
The fort occupies a triangular area of 75 hectares, of which 40 hectares accounts for the main structure. The north-east face, about 1,000 metres long, overlooks the Albert Canal cutting. The north-west face, looking over the Jeker / Geer valley, is protected by a wet moat, and about 450 metres long. The southern side (75 metres) has a dry moat.
There are main tunnel complexes and rooms on two levels within the hill, with stairways and ammunition lifts to the several gun positions on the top and at the side. There are also three false or decoy cupolas. The armament is reminiscent of that found in the Maginot Line forts; big rotatable guns under protective cupolas which could be raised and lowered. Some of these guns remain in situ. The fort remained off-limits in the charge of the Belgian Army for many years, but can now be visited, inside and on the roof. One of the lift / staircase shafts contains the dramatic wreckage left by German explosives used in taking the fort.
As well as the novelty of a glider borne assault, the attack marked the first use of shaped plastic explosives to disable the cupolas.