The Gevangenpoort (Prisoner's Gate) is a former gate and medieval prison on the Buitenhof. From 1420 until 1828, the prison was used for housing people who had committed serious crimes while they awaited sentencing.
Its most famous prisoner was Cornelis de Witt, who was held on the charge of plotting the murder of the stadtholder. He was lynched together with his brother Johan on 20 August 1672 on the square in front of the building.
In 1882, the Gevangenpoort became a prison museum. The 'gate' function was lost in 1923 when the houses adjoining the Hofvijver were taken down to build the street that now allows busy traffic to run by it.
Since 2010, museum visitors can view the restored art gallery that can be reached through a special staircase that connects the two buildings. The collection which hangs here is a modern reconstruction of the original 1774 art cabinet that was situated upstairs above the fencing school. The paintings are again upstairs, hanging crowded together on the walls in the style of the late 18th-century. In 1822 the collection was moved to the Mauritshuis which remains the formal owner of the paintings on display. During restoration activities, highlights of the permanent Mauritshuis collection have been temporarily displayed in the gallery.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.