The origins of Hrušov castle are not known, but it was probably built after the invasion of Tatars around 1253. From 1321 to 1344 it belonged to the family Levické and then became a royal property. In 1347 King Louis I of Hungary gave it to the governor Hrušov. The castle was destroyed by the Imperial army in 1708 and is in decay since then. However, its surviving walls induce a romantic atmosphere and provide a nice panoramic view.
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.