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:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.