Griffen castle was built between 1124 and 1146 by order of Bishop Otto of Bamberg. In an 1160 deed, Emperor Friedrich I mentioned Grivena as a Bamberg property.
In 1292 the Carinthian nobleman Count Ulrich von Heunburg with support of Archbishop Konrad IV of Salzburg occupied the fort in an uprising against Albert of Habsburg, the son of King Rudolph I of Germany and Duke Meinhard II. However Ulrich was abandoned by his allies and one year later had to leave the castle. In 1759 Bishop Adam Friedrich sold the Bamberg estates in Carinthia to Maria Theresa of Austria and the castle was incorporated into the Carinthian duchy.
About 1520 a large reconstruction of the castle took place as a protection against the threat posed by the Ottoman forces with a base amounted of about 4000 m², though the Turks never laid siege to Griffen. In 1659 a flash impact destroyed one of the towers and the decay of the castle began. In 1768 a last religious service took place and about 1840 the roofs were torn. In 2000 the preservation of the castle began. A steep footpath leads up the mountain to the ruins.
Within the mountain is the Griffener Tropfsteinhöhle (dripstone cave) with a length of 485m, which was not discovered until the late days of World War II. It is open to public and a natural landmark since 1957.
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.