King Frederik II and Tycho Brahe
King Frederik II (1534-1588 – ruled Denmark and Norway 1559 - 1588) was the first Danish King, who became interested in astronomy due to the scientific work of Tycho Brahe (1546-1601) - a famous Danish nobleman and astronomer, who developed the “Tychonian” system, which was a complicated astrological model of the solar system. King Frederik II was very impressed with the many important observations and results conducted by Tycho Brahe, that he granted the funding to establish two observatories on the island of Hven, which was situated in the Sound between Sweden and Denmark. The new observatories was built around 1576-1580 and named Uraniborg and Stjerneborg, and the first of its type in Denmark. The new astrological research institute was equipped with a laboratory for astrological experiments and many expensive astronomical instruments for precise measurements of the universal system.

The new astrological research institute and observatory Uraniborg was placed on the isle of Hven and built around 1576 by astronomer Tycho Brahe with support by King Frederik II, who was very interested in astronomy.

15 year old King Christian IV together with astronomer Tycho Brahe at Uraniborg in 1592. Tycho Brahe left the observatory on Hven 5 years later, due to a heavy dispute between the King and him. He died in Prague 1601.

King Christian IV and Tycho Brahe
King Frederik IIs son Prince Christian - later King Christian IV (1577-1648 – ruled Denmark and Norway 1588-1648) showed a great interest for astronomy too and often visited Tycho Brahe at his Uraniborg observatory on isle of Hven. As King Christian IV did not share the same enthusiasm for Tycho Brahe’s scientific methods and his interest for alchemy as his father had - Tycho Brahe fell into disgrace with the new King, who stopped all further funding of the two observatories on Hven. After the heavy dispute with King Christian IV, Tycho Brahe left Hven in 1597 and moved later to Prague. Shortly after his death in 1601, Tycho Brahe’s observatories Uraniborg and Stjerneborg was demolished and leveled to the ground.

The Trinitatis project and complex in 1749, with the Round Tower from 1642 - The Trinitatis Church from 1656 and the University library on the loft of the Chuch. The complex was especially built for scholars and students at Copenhagen’s University.

Picture from 1870 of the Round Tower, where horse carriages was a normal sight in the city. Trinitatis Church is right at the back of the tower and the complex was situated opposite the University Collegiums from 1840 called Regensen.

The Trinitatis Complex
After Tycho Brahe’s Uraniborg and Stjerneborg was destroyed and the lack of an having a scientific observatory in Copenhagen for the scholars and students at Copenhagen’s University – King Christian IV, who also was known as the great architect and builder of Copenhagen, took the initiative after advice from his own astronomer Christian Longomontanus to establish a new observatory, in the Latin Quarters of the City and named it the Round Tower. The foundation stone was laid in 1637 and was the first stage of the King’s Trinitatis Complex, which had the main objective to congregate three major facilities for scholars and students at the University such as an astronomical observatory – a University Church and a University Library.

The Round Tower at the back of the University dormitory has a height of 36 m and the diameter of the tower is 15 m. The observatory functioned until 1861 and was mainly used by the University.

The Round Tower is built with a 210 metre long spiral ramp, which leads to the top of the observatory and planetarium, as it was the King's wish to be driven by horse carriage up to the top.

The Round Tower
The Kings original idea from the start was to build an observatory identically like Tycho Brahe’s Stjerneborg on the top of the Round Tower with the exact diameter like Stjerneborg’s 15 m. The Tower was completed as an observatory with a little planetarium in 1642 and has a height of almost 40 m including the obsavatory. The Round Tower is built with a 210 metre long spiral ramp, which leads to the top, and on the uppermost facade of the tower (Top photo) there is a gilded inscription like a rebus. The rebus can be interpreted in the following way: Lead God, the right teaching and justice into the heart of the crowned King Christian IV, 1642 - the year when the tower was completed. King Christian IV's draft of it, written with his own hand, is kept at the Danish Record Office. The Round Tower is the oldest functioning observatory in Europe. Until 1861 it was used by the University of Copenhagen, but today, anyone can observe the night sky through the fine astronomical telescope of the tower in the winter period. Legendary astronomers having used the observatory include Ole Rømer (1644-1710) and Peder Horrebow (1679-1764). As a curiosity – a little piece of Tycho Brahe’s burial cloth obtained from his final resting place in Prague is displayed in the Round Tower’s collection.

The Trinitatis Church is built together with The Round Tower and completed in 1656, which were several years after the Round Tower was inaugurated by King Christian IV in 1642. The loft was used as a library for the University until 1861.

Trinitatis Church altarpiece and pulpit originates from 1756-67. In 1728 the church was damaged by a fire and was rebuilt again in 1731. Under the Choir there is a tomb where many prominent persons buried.

The Trinitatis church and University Library
As a part of the Trinitatis Complex, the Round Tower is built together with Trinitatis church as it was the King’s idea to build a University Church especially for scholars and students at Copenhagen’s University. The foundations stone was laid by the King in 1637 and the Church was inaugurated in 1656. In 1728 the church was damaged by a fire and was rebuilt again in 1731. The loft of the Trinitatis Church was used as a library for the University until 1861. The Altarpiece and pulpit is from 1756-1767 and there is a tomb under the Choir with many prominent persons buried.

There is a magnificent panorama view from the top of the Round Tower over the old Latin Quarters and other historic buildings in the Copenhagen skyline. In front are Copenhagen's Cathedral and the tower of the Town Hall.

A view towards east and Rosenborg Castle from 1634. One could easily imagine how King Christian IV experienced the view to his beloved Castle for the first time 40 m. over ground level around 1640, and beyond to the Sound and Sweden.

Beautiful view from the top
On the top of the Round Tower there is an exquisite view 40 m over the old part of Copenhagen and visitors can see some of King Christian IV's buildings like Rosenborg Castle - Old Stock Exchange (Børsen), Naval Quarters (Nyboder) - The Town Hall - Copenhagen's Cathedral and much more.

When the Russian Czar Peter the Great and his Empress Catherine I visited Copenhagen in 1716, they drove up to the top of the Round Tower in their Carriage, with the Czar on horseback in front. The event created massive headlines in the Copenhagen newspaper - Post-Rytter and was the talk of the town for a long time.

Manu types of attempts has been made to conqueror the top of the Round Tower beside walking. In 1902 a German tourist challenged his powerful German Beaufort car and drove as the first motorized vehicle up and down the spiral ramp. Beaufort was a German manufacturer of automobiles, who existed from 1902 – 1919.

Many Challenging rides to the top
King Christian IVs historical monument and landmark - The Round Tower – has been a subject for many challenging actions with its special is 210 metre long spiral ramp that leads to the top. In 1716, the royal Empress Catherine I of Russia drove up to the top of the Tower in a horse carriage, with her husband Czar Peter The Great of Russia in front on horseback, to enjoy the beautiful view over Copenhagen. The happening created headlines in the newspaper and was the talk of the town at that time. In 1902 a German tourist visited Copenhagen in his new motorized vehicle, a German Beaufort and drove his car to the top of the tower, as first motorized vehicle ascending the tower. A tradition every year in spring is the one wheel cycle rally Unicycle) up and down the towers spiral ramp and this very special arrangement by the Royal Roundtower Unicycle Race organizers gathers many participants and spectators. The world record for this special sporting event - up and down the ramp - is 1 minute 48.7 seconds, and was set in 1989.

Many different sports races and contest have been conducted on the spiral ramp to pursuit a record. A tradition every year in spring is the one wheel cycle rally up and down the towers ramp. This very special event is organized by the Unicycle Race Club and gathers many participants and spectators. The world record for cycling a one wheeler up and down the slope is 1 minute 48.7 seconds, and was set in 1989.

The famous Danish story writer Hans Christian Andersen (1805-1875), wrote the little fairytale about " The Tinder Box" in 1835, where the brave soldier met an old ugly witch, who told him about the old hollow tree with the three loaded money-chest that could make him rich, but were guarded by tree dogs - one with eyes as big as saucers, one with eyes as big as mill wheels and one with eyes as big as the Round Tower of Copenhagen.

The Round Tower and "The Tinder Box"
Many stories and anecdotes have been written about the Round Tower and one legendary one was written by the world famous story writer Hans Christian Andersen, who wrote the story about "The Tinder Box" in 1835, where the soldier meets the dog who sits on his money chest and with very dreadful eyes - as big as the Round tower of Copenhagen.