The Citadel of Lille is a pentagonal citadel built between 1667-1670. It is one of the most notable citadels designed by Sébastien Le Prestre de Vauban, the famous military engineer. It is remarkable for its size, the quality of the architecture, and the state of preservation today.
This 'Queen of Citadels' is the matrix of most citadels designed by Vauban. Established on the border of Flanders, it was part of a double-line of fortified towns between Gravelines, Dunkirk and Maubeuge-Rocroi. It delineated the famous Pré Carré ('square field') conceived by Vauban comprising 28 fortified cities. From Lille, Vauban supervised the construction of the many citadels and canals of the North, which controlled the border between France and Belgium.
Lille was taken from Spain by French troops in August 1667, and Louis XIV immediately ordered the construction of a fortress. Louis Nicolas de Clerville and Vauban proposed plans. Vauban are those which were chosen by the King. Work was started in 1668 under the direction of Lille"s master mason Simon Vollant. In 1671, the citadel was operational while Vauban continued to shape the city by constructing, a few steps away, a new neighborhood around the Rue Royale. The design of the citadel follows a simple but very effective idea: not one of its walls can be approached by the enemy without that being under fire from a nearby wall.
The citadel was constructed to the west of the city on marshland at the junction of the rivers Deûle and Bucquet. This allowed the use of swamp water and mud as a natural defense to make conditions more difficult for any possible enemy besieging the citadel. Through a system of locks and water gates, 1,700 hectares around the citadel could be flooded to a depth of 55 cm. A wide esplanade interrupted the plans, connecting the fort to the city. In 1750, a canal along the esplanade was drilled according to the plans drawn up by Vauban.
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.