Engelstein Castle was first mentioned in 1417 but it is probably much older. It is probable that at first it was a simple watch tower, guarding a nearby road crossing, which was upgraded to a water castle after the destruction of Hadmarstein Castle on the nearby Johannisberg mountain at the end of the 13th century. It was situated on a granite cliff surrounded on 3 sides by small lakes.
In 1531 the castle went to Benedikt Schaul who started to transform the still medieval fortress into a Renaissance castle. The Barons of Windhag continued this elaborate reconstruction and gave the castle its present outlook. The costs however were so enormous that the barons were soon heavily indebted after which the castle was confiscated at the end of the 16th century.
In 1619 Engelstein Castle was stormed by Imperial troops and plundered. In 1681 it was bought by Adam Anton Graf Gundemann, whose descendants owned the castle for the next 150 years. Then it went to the Barons of Geusau who owned it until 1916.
Several other owners followed until it was acquired by the industrialist Erich Meinl in 1964. By then the castle was in a bad state due to being plundered and neglected during and after World War II. Now the bailey is inhabited by a descendant of Meinl.
At present Engelstein Castle is privately inhabited and can thus not be visited.
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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.