The Château d'Étampes was a castle in the town of Étampes. The principal remains are of the 12th-century keep, the Tour de Guinette.
The Château d'Étampes was an early 10th-century stronghold of Robert the Pious, King of France, that comprised both a palace proper and motte. Between 1130 and 1150, a new castle was created overlooking the valley, culminating in a strong keep or donjon: the present Tour de Guinette. The Château was extended under later kings, notably Philip II of France, but suffered through sieges in the Hundred Years War before having been ordered destroyed by Henry IV of France, after which only the keep remained.
The architectural aspects of this former royal castle are known from contemporary images, including the Très Riches Heures du duc de Berry. Tour de Guinette was in the center of the castle and was surrounded by a rectangular curtain wall punctuated by corner towers. This wall was, in turn, enclosed by two additional walls providing layers of defense for the keep.
The surviving keep stands roughly 27 meters tall and is a quatrefoil plan (much like a four-leaf clover). Divided into four stories, first-floor access may originally have been reached from the enclosure wall. This interesting plan is the result of tactical experimentation that the keep underwent during the mid-12th century to improve the defense of towers against missiles and to reduce dead ground. The circular lobes deflect missiles, and allow defenders to cover the foot of the walls from the summit of the keep. The plan resembles the keeps of Ambleny and nearby Houdan. Clifford's Tower, part of York Castle in York, England, is believed to have been inspired by Étampes.
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.