The Liebenstein Castle , now a ruin , is on a granite cone north of Plößberg. The hill fort was first mentioned in 1125. In 1292 the family who built the Liebenstein family died out and the castle was sold by Theodorich von Parsberg to the abbot Theoderich of the Waldsassen monastery in 1298 . Theodoric carried out extensive repairs , and the castle was given an outer wall under Abbot Franz Kübel . With the abolition of the monastery during the Reformation, the castle was sold to the Tirschenreuth citizen Anton Mehler and his descendants. After 1634, after it had previously been the seat of the judges' office, it was no longer inhabited and fell into disrepair.
On granite cone of Castle Hill were up in the 1950s several quarries, are also obtained immediately below the ruins themselves. Originaer few foundations of the keep , since the summer of 2007 parts are built up the walls again.
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.