Probably built in 837 by Orso I, the Monte Sant'Angelo Castle has bastions of different ages. The most ancient part, called Torre dei Giganti ('Giants' Tower') is a pentagonal tower 18 m-high, with walls 3.7 m thick. The first documents on its history dates back to 979; later, it was the residence of Rainulf I of Aversa and the Robert Guiscard, who built the Norman Tower and the Treasure Hall.
Emperor Frederick II restored the construction to use it as residence for his mistress Bianca Lancia, while under the Angevines it was used mainly as prison. Later, from 1464 to 1485, the fortress was the residence of the exiled Albanian condottiero Skanderbeg. The castle was largely rebuilt in the late 15th century by Ferdinand I. According to a legend, the castle is currently home to the ghost of Bianca Lancia, whose sighs can be heard especially in the winter time. Today the castle is used for exhibitions.
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.