In 1178, Ferdinand II of León donated the Ponferrada city to the Templar order for protecting the pilgrims on the Way of St. James who passed through El Bierzo in their road to Santiago de Compostela. Their castle was originally a hill-fort and later a Roman citadel. Templar knights took possession of the fortress and reinforced and extended it to use it as an inhabitable palace.
However, the Templars were only able to enjoy the use of their fortress for about twenty years before the order was disbanded and its properties confiscated in 1311. Several noble houses fought over the assets until Alfonso XI allotted them to the Count of Lemos in 1340. Finally the Catholic Monarchs incorporated Ponferrada and its castle into the Crown in 1486. Most of the walls were removed and used in local construction projects.
The building has an irregular square plan and the outstanding features are, above all, the entrance which involves crossing the moat on a drawbridge and, further on, two large towers with crenellations joined by an arch. Its twelve original towers reproduced the shapes of the constellations.
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.