Fort de Lantin The Fort de Lantin is one of twelve forts built as part of the Fortifications of Liège in the late 19th century in Belgium . It was built between 1881 and 1884 according to the plans of General Henri Alexis Brialmont . Contrasting with the French forts built in the same era by Raymond Adolphe Séré de Rivières , the fort was built exclusively of unreinforced concrete , a new material , rather than masonry . The fort was heavily bombarded by German artillery in the Battle of Liège . Lantin was never upgraded like the other forts of Liège and retains its character as a Brialmont fort . It is preserved as a museum and may be visited by the public . Description . The Fort de Lantin is located about northwest of the center of Liège . The fort forms an isosceles triangle whose base is long and whose sides measure . A deep by ditch encircles the fort . The principal armament was concentrated in the central massif . The ditches were defended in enfilade by 57mm guns in casemates resembling counterscarp batteries , firing at shot traps at the other end of the ditch . It is one of the smaller forts of Liège . With the exception of the Fort de Loncin , the Belgian forts made little provision for the daily needs of their wartime garrisons , locating latrines , showers , kitchens and the morgue in the fort ' s counterscarp , a location that would be untenable in combat . This would have profound effects on the forts ' ability to endure a long assault . 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 . The Brialmont forts placed a weaker side to the rear to allow for recapture by Belgian forces from the rear , and located the barracks and support facilities on this side , using the rear ditch for light and ventilation of living spaces . In combat heavy shellfire made the rear ditch untenable , and German forces were able to get between the forts and attack them from the rear . The Brialmont forts were designed to be protected from shellfire equaling their heaviest guns : 21 cm . The top of the central massif used of unreinforced concrete , while the caserne walls , judged to be less exposed , used . Under fire , the forts were damaged by 21 cm fire and could not withstand heavier artillery . Armament . Lantin ' s armament included two double 15 cm gun turrets , two double 12 cm gun turrets and 57mm gun turrets . It also mounted an observation turret with a searchlight . Rapid - fire 57mm guns were provided in casemates for the defense of the ditches and the postern . 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 ) . The fort was provided with signal lights to permit communication with the neighboring Fort de Loncin and Fort de Liers . The guns were fired using black powder rather than smokeless powder , producing choking gas in the confined firing spaces that spread throughout the fort . First World War . In 1914 the Fort de Lantin was one of the last Liège forts to suffer German bombardment . Liège first came under attack on 6 August 1914 . When the Liège proved unexpectedly stubborn , the Germans brought heavy siege artillery to bombard the forts with shells far larger than they were designed to resist . Lantin was heavily bombarded starting 10 August . It surrendered the next day , due to the asphyxiating atmosphere within . Present . Lantin was not upgraded in the 1930s as part of the Fortified Position of Liège , remaining essentially as it was built by Brialmont . The fort was acquired by the preservation organization " Les Amis du Fort de Lantin " from the Ministry of Defense in 1983 , and is open for public tours at stated times .