Neuhaus castle dates probably back to the 13th century. It may have been built on the site of earlier 12th century fortified house. The pentagonal tower was added in the 14th century and the castle was rebuilt during the 16th century. The traffic on the Danube has been able to deny with chain from the chain tower, located below the castle. Neuhaus was besieged at least in 1381, 1386 and 1389.
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.