The Ponts Couverts are a set of three bridges and four towers that make up a defensive work erected in the 13th century on the River Ill in the city of Strasbourg in France. The three bridges cross the four river channels of the River Ill that flow through Strasbourg's historic Petite France quarter. The Ponts Couverts have been classified as a Monument historique since 1928.
Construction of the Ponts Couverts commenced in 1230, and they were opened in 1250. As a defensive mechanism, they were superseded by the Barrage Vauban, just upstream, in 1690, but remained in use as bridges. As built, each of the bridges was covered by a wooden roof that served to protect the defenders who would have been stationed on them in time of war. These roofs were removed in 1784, but name Ponts Couverts (covered bridges) has remained in common use ever since.
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.