Rabenstein Castle was built around 1100 to protect nearby Sankt Paul im Lavanttal. It began as a mere watchtower built on a tall hill. Rabenstein became a castle when Engelbert I Sponheim, Margrave of Istria founded St. Paul's Abbey in 1091 in order to protect the abbey and town around it. The castle was occupied by the Rabensteins (whose name henceforth stuck to the structure) until 1200, the Archbishop of Salzburg until 1300. in 1636 the castle was destroyed by fire and left to decay.
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.