The amphitheatre of Catania is the most complicated and largest of all the amphitheatres in Sicily. It was built in the Roman Imperial period, probably in the 2nd century AD, on the northern edge of the ancient city at the base of the Montevergine hill. Only a small section of the structure is now visible, below ground level, to the north of Piazza Stesicoro.
The external diameter was 125 x 105 metres, while the external circumference was 309 metres. From the theatre's dimensions it can be calculated to have held 15,000 spectators and almost double that number with the addition of wooden bleachers for standing spectators. According to an uncertain and unconfirmed tradition, it was intended that naumachiae (staged sea battles) take place in the amphitheatre, using the ancient aqueduct to fill the arena with water.
According to Cassiodorus, in the 5th century, Theodoric, King of the Ostrogoths, allowed the inhabitants of the city to spoliate the theatre for building material for the construction of stone buildings.
In the 13th century, according to tradition, the amphitheatre's vomitoria (entranceways) were used by the Angevins to enter the city during the Sicilian Vespers. In the following century, the entrances were walled up and the ruins were incorporated into the Aragonese fortifications (1302).
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.