Nassenfels castle dates from the 12th-13th century. The first reference to the castle is dated to 1245, when Count Gebhard III of Hirschberg was assassinated when he was besieging Nassenfels castle. The castle was reconstructed and enlarged later and the current appearance dates from c. 1400. The three towers were built by bishop Friedrich von Oettingen. Nassenfels was again restored in 1464 and 1699. in 1807 the castle was sold to private owners and used as a quarry.
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.