Warsaw Citadel. It is a fortress built by the tsarist authorities after the Polish-Russian war in 1831 r. Built to intimidate the city's inhabitants against possible future protests and to protect the Russian garrison in the city. It was erected near the former Aleksandrowskie barracks. Its construction was accompanied by the demolition of a large part of the buildings in Żoliborz. The first stage according to the design. Ivan Dehn took place in the years 1832-36. The citadel was built on the plan of an irregular polygon with 4 bastions and a semi-bastion connected by curtain walls. The building was surrounded by earth embankments, pit and wall Carnota. In years 1849-64 built around the citadel 6 outer forts. From the beginning of its existence, the citadel also served as a heavy prison. Here during the January Uprising, the trial of members of the Grand Proletariat and the speeches in 1905-07 a court martial was located. The slopes of the citadel were the site of the execution of many Poles, it is commemorated by the Death Gate and the cemetery situated on the side of the Vistula River. They were stationed in the citadel in the interwar period: 21 pp. im. "Children of Warsaw" and 30 Kaniowski Rifle Regiment. During World War II, the Nazis imprisoned and murdered many Poles here. Currently, the citadel is one of the best-preserved large defensive architecture complexes in Poland. The famous Pavilion 10 houses a branch of the Independence Museum.