Join us for a quick virtual tour to the tower platform, 34.8 metres above street level.

How long is the Spiral Ramp? How much does the Round Tower weigh? How large is the Library Hall? Get the answers to these questions and learn much more about the measure and weight of the Round Tower here.

King Christian IV did not take any shortcuts when he built the Round Tower. The obvious choice would have been to place the university’s new observatory, which the Round Tower was to house, at a reasonable distance from the vibrant capital. But the King wanted it otherwise.

The Round Tower’s gateway is the beginning of the tower, also in a more figurative sense. It contains nothing less than the Round Tower’s birth certificate, generously spiced with traces of changing kings, who have found it important to make their mark in this central location.

“At first sight, this idea may seem rather bold,” the architect Anton Rosen wrote when presenting a proposal to roll the Round Tower over to the side of the Trinity Church. The proposal was just one of several creative solutions to the increasing number of road users, who passed the tower around 1900.

Rebuses exist in order to be solved but apparently it has not always been easy for the ordinary Copenhagener to decipher the golden inscription on the Round Tower's façade, which Christian IV himself has sketched. For how is Denmark's most famous rebus to be understood?

It did not come out of the blue that the round walls of the Round Tower are built in masonry of alternating red and yellow bricks. The colours were meant to send a signal to the world that this was a royal edifice.

Until 1992, a large crack on the Round Tower’s footing testified to the incident when a bunch of yggenyks stole the old tower. Fortunately, the small three-legged birds were persuaded to put it back in place since they not only have a preference for historic buildings but also for cookies.

The only leaning tower in the world is not the one in Italy. For while the Leaning Tower of Pisa is known to be leaning but is also round, the Round Tower is known to be round but is, in fact, also leaning.

The city water contained mosquito larvae and leeches when a master shoemaker established a serving stall of drinking water at the foot of the Round Tower.

When Denmark’s first revue premiered on New Year's Eve 1849, the Round Tower appeared on stage in the shape of an almost two metres tall cardboard figure running for a parliamentary election.

To mark the Round Tower’s 300th anniversary in 1942, a violet commemorative stamp worth 10 øre was issued and printed in well over eight million copies. This was the first but by no means the last time the tower appeared on postal stamps.