The Archcathedral Basilica of the Assumption of the Blessed Virgin Mary and Saint Andrew in Frombork was constructed during 1329-1388. The astronomer and mathematician Nicolaus Copernicus worked there as a canon (1512–16 and 1522–43). He wrote his epochal work, De revolutionibus orbium cœlestium in Frombork. Shortly after its 1543 publication, Copernicus died there and was buried in the cathedral where his grave was thought to have been found by archaeologists in 2005. This was subsequently confirmed in November 2008 by the publication of the results of DNA tests on fragments of bone and hair found on the skeleton; hair that matched two strands of hair which belonged to Copernicus and are currently located in Uppsala University.
In the northwest corner of the cathedral grounds is Copernicus' tower, and in the southwest corner an octagonal building with a square bell tower and a small planetarium and a Foucault's pendulum. Frombork suffered destruction during the Polish–Swedish wars. Between 1626 and 1635 it was occupied by Gustavus Adolphus of Swedenwho looted the cathedral and removed many cultural artefacts, including Copernicus' manuscripts to Sweden.
The town and cathedral were badly damaged in World War II. After the war the cathedral was meticulously reconstructed.
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.