There have been settlements on the site of Châtel-Argent castle since prehistoric times and through the Roman Era. There is a chapel dedicated to Saint Columba of Sens which was built sometime between 1050 and 1070. The castle first appears in a document in 1176 as Castrum Argenteum. The castle was improved around 1275 under the direction of Count Peter II's architect James St. George and castle grew to the configuration we see today. This castle had always been owned by the counts and the dukes of Savoy.
The ruins can be accessed from Villaneuve by walking The Rampa, a staircase carved into the rock of the valley wall. The castle is located in the town of Villeneuve in the Aosta Valley region, at about 10 km west of the city of Aosta. The most prominent feature left in the ruins is its watchtower keep measuring just under 10 meters in diameter which overlooks the town below. The ruins themselves cover about 6,300 square meters. When the castle was whole, it was estimated to be able to hold 700 people in times of danger.
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.