Warsaw 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 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.
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 casemates were built, providing cells for 2,940, mostly political, prisoners. Most notably, is included the Tenth Pavilion. It 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.References:
The castle of La Iruela, small but astonishing, is located on the top of a steep crag in Sierra de Cazorla, Segura y Las Villas Natural Park. From the castle, impressive views of the surrounding area and of the town can be enjoyed.
The keep dates from the Christian era. It has a square base and small dimensions and is located at the highest part of the crag.
There are some other enclosures within the tower that create a small alcázar which is difficult to access.
In a lower area of the castle, protected with defensive remains of rammed earth and irregular masonry, is an old Muslim farmstead.
After a recent restoration, an open-air theater has been built on La Iruela castle enclosure. This theater is a tribute to the Greek and Classic Eras and holds various artistic and cultural shows throughout the year.
The first traces of human activity in La Iruela area are dated from the Copper Age. An intense occupation continued until the Bronze Age.
Originally, La Iruela (like Cazorla) was a modest farmstead. From the 11th century, a wall and a small fortress were built on the hill to protect the farmers.
Around 1231, don Rodrigo Ximénez de Rada, Archbishop of Toledo, conquered La Iruela and made it part of the Adelantamiento de Cazorla. Over the Muslim fortress, the current fortress was built.
Once the military use of the fortress ended, it was used as cemetery.