The ancient name of Pietra Ligure was La Pietra , and referred to the imposing calcareous rock that is found to the east of the historical center, above which the Roman castrum was built. The castle, enlarged in the period of the barbarian and Saracen invasions (6th-9th century), was a bishop ‘s property and reached its present size in the 16th century. It is believed that this natural barrier, easily defensible, constituted a border point between the Byzantines and the Lombards .
The Byzantine castrum was probably destroyed by King Rotari, but in the same site the medieval castle, stronghold of the bishops of Albenga, was built in the 12th century , subject then to frequent attacks by the Del Carrettos of Finale . To the west of the castle a hamlet developed, surrounded by turreted walls and endowed with five gates: the port of the marina protected by a bastion to the south, the gate of Santa Caterina near the homonymous rural oratory to the north, the door of the porch protected by the tower of via Rocca Crovara and the royal gate to the west, the door to the slaughterhouse to the east. After various vicissitudes, the village was definitively ceded by Pope Urban VI to Genoa , in 1385 , and acquired considerable importance as an advanced point of the Republic between the Finale and Loano , fiefdom of the Doria .
The castle remained the property of the bishops of Albenga, who sold it to the Arnaldo at the end of the fourteenth century . It then passed into the possession of other patrician families and was enlarged in 1550 with the addition of a wing facing south-west, an arch in the eastern part in addition to the two sentry boxes. Due to the Saracen raids the upper square was armed with two large cannons, which were sent back to Genoa at the end of the 18th century in view of the French invasion. The medieval part, at the end of the fifties of the twentieth century , has been restored and transformed into a meeting place. The solid masonry resting directly on the rock, the impervious position, the vaulted passages and the low rooms of the dungeons known as “Grimaldina”, due to the fact that two Grimaldi brothers from Monaco were imprisoned there at the end of the fourteenth century, justify the importance of the castle exercised in the local defense system.
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.