Mühlbacher Klause (Chiusa di Rio Pusteria) castle was built by Sigmund, Duke of Tyrol, between 1458 and the 1480's. It replaced an older fort, built in the 13th century and which was situated about 600 meters west of the present location.
Both fortifications were built here to control the passage through the Pusteria valley which was the border between the counties of Gorizia and Tyrol.
In the 18th century an administration wing, once annexed to the residential building, was destroyed by a flood. Around 1871 the northeastern tower was partly destroyed.
The most recent wartime involvement of the castle dates from the so-called French War at the beginning of the 19th century, when Napoleon's troops were faced by the Tyrolese militia.
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.