Finished in 1259, Stolzenfels was used to protect the toll station at the Rhine, where the ships, back then were the main transport for goods, had to stop and pay toll. Over the years it was extended several times, occupied by French and Swedish troops in the Thirty Years' War and finally, in 1689, destroyed by the French during the Nine Years' War.
For 150 years the ruins decayed, until in 1815 they were given as a present to Frederick William IV of Prussia by the city of Koblenz. Following the romantic traditions, the prince started to completely rebuild the castle after 1826 as a summer residence. Supported by famous neoclassic architect Karl Friedrich Schinkel, the castle was completely remodeled in the then fashionable neo-Gothic style, aiming to create a romantic place representing the idea of medieval knighthood - the architects even created a tournament site.
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.