Ruttenstein Castle was first time documented in 1209, in a deed issued by Duke Leopold for the Baumgartenberg Monastery, where it is mentioned under the name Rotenstein. The existing structure of the high castle, however, suggests that the castle is significantly older. The construction period likely falls in the first half of the 12th century, although this is not documented. It is probably a foundation of the Counts of Clam-Velburg.
The walls of the formerly massive pentagonal keep are now only partially preserved, tapering to a point and visibly towering over the site. The former residential wing in the west retains three of its walls. Above them, a viewing platform has been constructed, accessible via wooden stairs. Clearly recognizable, though also only partially preserved, is the early Gothic castle chapel located near the stone steps to the residential building. The main castle itself was protected on the north, south, and east by a mighty ring wall, which is still partially preserved today, and from which seven wall towers protruded.
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.