Fort de Loncin was constructed between 1881 and 1884 according to the plans of General Henri Alexis Brialmont.

The experimental nature of the new material, and the design features of the fort, led to unintended consequences in combat action.

The Fort de Loncin is located about 7 kilometres (4.3 mi) west of the centre of Liège, in the direction of Brussels and Tongeren, in the municipality of Ans.

Even at Loncin, the service areas were placed directly opposite the barracks, which opened into the ditch in the rear of the fort (i.e., in the face towards Liège), with lesser protection than the two "salient" sides.

[3] Loncin was the only Liège fort to be provided with mechanical ventilation, allowing gun and sewage gases to be evacuated, and improving its combat endurance until debris blocked the exhaust.

[7] The large weapons were all German products, made by Krupp in Essen, but the armor was by Cockerill (Belgium), Ateliers de Creusot (France) or Grüson (Germany).

Loncin was massively bombarded for three days from 12 to 15 August, before one of its two magazines, with twelve tons of explosive, blew up.

"[17]The 42 cm Big Bertha howitzer, the secret weapon of the German army in 1914, quickly became widely celebrated.

The principal reason for the destruction of the Fort de Loncin was that the ammunition magazines had been placed too close to the surface, and had never been upgraded since their construction to deal with improved artillery.

[20] After the war Belgian sentiment of admiration for the fort's defenders resulted in a public subscription to erect a monument that King Albert I dedicated on 15 August 1923.

A number of other commemorative monuments were placed at the site, including the flamme du souvenir, a figure of a man thrusting a torch from under the earth.

In October 2007, after a project of mine and explosives clearance, 2,500 shells, representing 142 tons of munitions, were extracted.