Warsaw Citadel Warsaw Citadel ( Polish : Cytadela Warszawska ) is a 19th - century fortress in Warsaw , Poland . It was built by order of Tsar Nicholas I after the suppression of the 1830 November Uprising in order to bolster imperial Russian control of the city . It served as a prison into the late 1930s , especially the dreaded Tenth Pavilion of the Warsaw Citadel ( " X Pawilon Cytadeli Warszawskiej " ) ; the latter is a museum since 1963 . History . The Citadel was built by personal order of Tsar Nicholas I after the 1830 November Uprising . Its chief architect , Major General Johan Jakob von Daehn ( " Ivan Dehn " ) , used the plan of the citadel in Antwerp as the basis for his own plan ( the same that was demolished by the French later that year ) . The cornerstone was laid by Field Marshal Ivan Paskevich , " de facto " viceroy of Congress Poland . The fortress is a pentagon - shaped brick structure with high outer walls , enclosing an area of 36 hectares . Its construction required the demolition of 76 residential buildings and the forcible resettlement of 15 , 000 inhabitants . Work on it commenced May 31 , 1832 , on the site of a demolished monastery and of the estate of " Fawory " . Officially it ended May 4 , 1834 , to mark the 18th birthday of Russian Crown Prince Alexander , for whom it was named . In reality , however , the fortress was not completed until 1874 . The cost of construction came to 11 million rubles ( roughly 8 . 5 tonnes of pure gold or 128 million euro at today ' s ' prices ) , a colossal sum by 19th - century standards , and was borne entirely by the city of Warsaw and the Bank of Poland , as yet another punishment for the failed uprising . In peacetime , some 5 , 000 Russian troops were stationed there . During the 1863 January Uprising , the garrison was reinforced to over 16 , 000 . By 1863 the fortress housed 555 artillery pieces of various calibers , and could cover most of the city center with artillery fire . About the fortress , 104 prison casemate s were built , providing cells for 2 , 940 , mostly political , prisoners . Most notably , is included the Tenth Pavilion . The list of Poles imprisoned and / or executed there up through World War I reads like a " Who ' s Who " of notable patriots and revolutionaries . They include persons as diverse as Apollo Korzeniowski , writer , political activist and father of Joseph Conrad ; Romuald Traugutt , leader of the 1863 January Uprising ; Jarosław Dąbrowski , later military chief of the 1871 Paris Commune ; Feliks Dzierżyński , a leader of the Russian Revolution of 1917 and founder of the Cheka secret police ; the Marxist theoretician and revolutionary , Rosa Luxemburg ; the future Marshal of Poland , Józef Piłsudski ; Piłsudski ' s political archrival , Roman Dmowski ; and Eligiusz Niewiadomski , assassin of Poland ' s first president , Gabriel Narutowicz . The Citadel ' s Tenth Pavilion has , since 1963 , served as a museum . Well before the turn of the 20th century , it was apparent that such traditional fortifications had been made obsolete by modern rifled artillery . The Tsarist authorities had planned in 1913 to raze the fortress , but the process had not begun before the outbreak of World War I . In 1915 Warsaw was occupied by German forces with little opposition from the Russian garrison , which abandoned the fortress and withdrew east . The Germans blew up several of its structures , but the main part of the Citadel remained intact and German forces performed a mass execution of 42 people in 1916 . After Poland regained her independence in 1918 , the Citadel was taken over by the Polish Army . It was used as a garrison , infantry training center , and depot for materiel . During the 1944 Warsaw Uprising , Citadel ' s German garrison prevented linking between the city center and the northern Żoliborz district . The fortress survived the war and in 1945 became again Polish Army property .