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Round Tower (Rundetårn) - Copenhagen - Astronomy

The Round Tower (Rundetårn) is one of the oldest astronomical observatories in Europe, and it is the oldest one still in use today.  The Round Tower is situated in downtown Copenhagen (København on one of the main walking streets. The tower stands 34.8 meter high and it is attached to the Trinitatis Chuch (Trinitatis Kirke).

The tower was constructed during the reign of King Christian 4 who is perhaps Denmark’s most famous historical monarch.  Construction of the tower began in 1637, and it was finished in 1642. It is incredible to think that the observation tower was completed in the same year that Galileo Galilei died in Italy after 27 years of house arrest for his heretical claims that the Earth goes around the sun, and not the other way around.  Also, the Trinitatis Chuch which was completed shortly after the tower in 1656 was attached directly to the Round Tower. In Europe the intermingling of science and religion was quite uncommon at this time.  This certainly shows how progressive Denmark was during the mid 17th century.

The Trinitatis complex (the tower, the church and the library) was constructed as a place for scholars to the study the heavens in the observatory, and to pray to the heavens in the church. The library was used by the University of Copenhagen for approximately 200 years until 1861. 

The Round Tower has a unique architectural feature to Europe.  The tower has an enormous spiral walkway to the top of the tower. The walkway is 210 meters long and it is wide enough to accommodate a car. In fact there have been quite a few cars to drive to the top of the tower. The first car to drive to the top was a German Beaufort in 1902. The Round Tower was actually designed to allow horse drawn carriages to ride to the top of the tower. Why anyone would need their carriage to ride to the top of a tower is anyone’s guess.  While visiting King Frederik IV in the Danish Capital in 1714, Peter the Great of Russia rode his horse to the top of the Round Tower.  Every spring there is a unicycle race to the top of the tower and back down to the bottom.  The record for gruelling feat is 1 minutes 48.7 seconds and it was set in 1989.   

The two most famous astronomers to work and study at the Round Tower were Ole Romer and his assistant Peder Horrebow.  Ole Romer made the first accurate calculation of the speed of light in 1676. 

The tower is open for daily visits with the exception of Christmas and New Years holidays. The Round Tower has regular classical and new age music concerts; as well as temporary art and design exhibitions.  All of these are housed inside the church section of the building complex.    

The most impressive feature of the Round Tower is that in the evenings from mid-October until mid-March the public is welcome to come and view the stars and planets through the observatory’s powerful telescope.  Also during the summer months the public is welcome to come and have a look at the sun the observatory’s telescope.  There are very few places in the world where members of the public can have the opportunity to view the wonders of space through a professional astronomer grade telescope.    
There are plenty of old astronomical instruments on display, and the tower has a beautiful panoramic view of the Copenhagen skyline. The Round Tower is well worth a visit if you happen to be in Copenhagen.

The Round Tower
Koebmagergade 52a
DK-1150 Copenhagen
Tel +45 33 73 03 73

LastUpdate: 2015-05-05 13:42:39