The Gvozdansko Castle was probably built in the second half of the 15th century, due to mining rights of Croatian Zrinski noble family. The castle was first mentioned in 1488. Nikola III Zrinski and his son Nikola Šubić Zrinski frequently came to Gvozdansko in order to inspect the mines and the mint.
The Turks attempted to conquer the Gvozdansko Castle on several occasions. Three major attempts were made in 1561 by Malkoč-beg, in 1574 by Ferhad-beg, and in 1576 by Kapidži-pasha. The final siege by Ferhat-paša Sokolović with 10,000 soldiers, which was fought from 3 October 1577 to 13 January 1578, was much better prepared. That Siege of Gvozdansko ended with an Ottoman victory, after long and bloody siege. Ottomans managed to break into castle only after last defenders froze to death in harsh winter, having no wood or anything else to light the fire, on 13 January 1578.
Ottoman rule in Gvozansko lasted until 1718. Ottoman commander was stunned by the brave Croatian defenders, after witnessing frozen bodies of defenders still holding their muskets on combat positions in the ruined castle.
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.