Fort de Tancrémont The Fort de Tancrémont is a Belgian fortification located about south of Pepinster . The fort was built in the 1930s as part of the fortified position of Liège , augmenting the twelve original forts built to defend Liège in the 1880s with four more forts closer to the Belgian frontier with Germany . The fort was the last Belgian fort to surrender to German forces in the opening days of World War II , following the dramatic assault on Tancrémont ' s sister fort , Fort Eben - Emael . Tancrémont has been preserved and may be visited by the public . Situation . The fort is the southernmost of the four 1930s forts , located about southeast of Liège . Tancrémont and Fort d ' Aubin - Neufchâteau are smaller than Eben - Emael and Fort de Battice . Collectively , the line was known as the Fortified Position of Liège I ( " Position Fortifiée de Liège 1 " ( PFL I ) ) , the original Liège forts constituting PFL II . Description . The Fort de Tancrémont was a development of the original Belgian fortifications designed by General Henri Alexis Brialmont before World War I , a relatively compact ensemble of gun turrets and observation posts disposed on a central massif of reinforced concrete , surrounded by a defended ditch . This was in contrast with French thinking for the contemporary Maginot Line fortifications , which were based on the dispersed " fort palmé " concept , with no clearly defined perimeter , a lesson learned from the experiences of French and Belgian forts in World War I . The new Belgian forts , while more conservative in design than the French " ouvrages " , included several new features as a result of World War I experience . The gun turrets were less closely grouped . Reinforced concrete was used in place of plain mass concrete , and its placement was done with greater care to avoid weak joints between pours . Ventilation was greatly improved , magazines were deeply buried and protected , and sanitary facilities and general living arrangements for the troops were given careful attention . Tancrémont was among the smaller of the new Belgian forts , armed with a maximum gun caliber of 75mm . These guns did not have sufficient range to provide mutual support between neighboring fortifications . The Fort de Tancrémont comprised five combat blocks on a ridge between Pepinster and Theux . Only the tops of the blocks were visible , with the majority of the fort sunk into the ground . The fort also included counterscarp positions arranged to fire along the ditches with 47mm guns , machine guns and grenade launchers , designated C . II , C . III and C . IV . Two ventilation blocks designated B . O . and B . P . provided air . B . P . was located above the main living accommodations and was the combat entrance , armed with machine guns , while O was an emergency exit . Both B . O . and B . P . were outside the defended perimeter , above deeply buried galleries . The fort included a false cupola , designated " K . " The subterranean galleries totaled slightly less than of passages buried between and below the surface , linking troop accommodations , a command post ammunition magazines and utility plants . Construction was directed by Lieutenant Victor Gérard . Unlike its three sisters , Tancrémont lacked a rolling drawbridge entrance , a result of its late completion . The main 75mm guns were Bofors Model 1934 , made at the Fonderie Royale des Canons ( FRC ) . The 47mm guns were FRC Model 1936 . Tancrémont was intended to receive 120mm guns like Eben - Emael and Battice , but block B . III received only machine guns . Personnel . In 1940 Tancrémont was commanded by Commandant - Captain Devos of the 4th Battalion of the Liègeois Fortress Regiment , commanded by Major Parmentier . History . The Fort de Tancrémont was completed on 8 August 1938 , the last of the new forts in the Fortified Position of Liège . In 1940 the fort was commanded by Captain Abel Devos . At the time of the German invasion of Belgium , some construction was taking place at the fort . The main fort was accessible by workers ' excavations , compromising security and protection . On 12 May 1940 the Germans attacked , having already captured Eben - Emael the previous day . The German commander , General Fedor von Bock , demanded the surrender of Battice and Tancrémont on 20 – 21 May after the German capture of Aubin - Neufchâteau had resulted in significant casualties on both sides . Battice complied on 22 May , but Tancrémont refused . The Germans therefore bypassed Tancrémont . The fort held out through the capitulation of the Belgian field army , Captain Devos believing that the surrender applied only to field forces . Devos eventually obtained written confirmation of the general surrender order signed by General Spang and surrendered the fort the day after the general capitulation , on 29 May 1940 . The garrison was sent by the Germans to labor in Silesia . Present day . The fort is preserved and open for public tours . The main body of the fort , in its defensive enclosure , is just to the south of the main road . Blocks B . O . and B . P . are across the road . The fort is administered by the Amicale du Fort de Tancrémont , descended from the Fraternelle du Fort de Pepinster organized by Captain Devos in September 1942 to reunite the troops of the garrison with their families .