Château de Liettres was probably built some years before 1479 by Sir Simon de Luxembourg, provost of the church of Saint-Omer. In that year it was burned by the progressing army of Maximilian I of Austria.
In 1542 Liettres Castle was again burned and partly destroyed by the troops of the Duke of Vendome. Shortly thereafter the castle was bought by Jean de Zomberghe after which it remained in the hands of his descendants.
Liettres Castle was built on an artificial plot of dry ground in the marshy valley of the La Laquette stream which also fed its moats. During the course of centuries it underwent several transformations. In 1720 the main building was rebuilt. It consists of several buildings forming a square with strong cylindrical towers. It has walls of 2.5 meters up to 5 meters thick in some towers.
At present the castle is privately owned and inhabited.
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.