The first documented mention of Burg Reichenstein dates from 1208. Following this, the Burg Reichenstein was attributed to Ludwig III of Reichenstein between 1310 and 1320 for the protection of his territory and possibly as a customs station.
Since the 16th century, it has been considered a ruin and was destroyed in 1618 by its then-owner Count zu Wied when the Count of Sayn intended to acquire it. Since then, the ruin has continued to decay and was in private ownership until the 20th century. In recent years, the ruin has been managed by an association, and extensive restoration work has been carried out, including the establishment of the Walpodenstube, which can accommodate approximately 30 guests.
The castle can be visited at certain times, and festivals and events also take place in and around the castle. In addition to the foundations of the other castle buildings and a partially filled-in well, which was formerly 40 meters deep, the still towering ruins of a four-story residential tower give the ruin its characteristic appearance.
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.