Le Bas-Plessis was originally an ancient fiefdom and lordship under the jurisdiction of Montrevault. In the 15th century, it belonged to the Chenu family, who obtained it through the marriage between the knight Pierre Chenu and Jeanne Bérard, lady of Bas-Plessis, the daughter of Jean Bérard and Gervaise de Marigny.
Pierre Chenu, a knight of the Order of the King, obtained on December 23, 1602, the right to establish the land as a chatelain with the right of provostship, seal, measurement, baking oven, and mill. This right was granted to him by his suzerain, Charles Turpin, Count of Montrevault.
On November 2, 1666, François de Villoutreys and his wife, Renée Chenu, took possession of it.
During the Vendée War, the castle provided refuge to the wounded Lescure. In 1794, the feudal castle was set on fire during a battle, and only two towers remained, bordering the current pond. The castle was rebuilt in a neo-classical style in 1845 and expanded with a wing in 1875 to house the library of the Marquis de Villoutreys.
The remains of the medieval castle consist of two round towers with conical slate roofs. The first floor of the north tower serves as a chapel. A curtain wall connects these two towers. These are the parts that are listed as historical monuments.
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.