@Walter Hinteler,
Always fun to learn something new.
Runde Taarn was/is an astronomical observatory. so need for taking canons up or down.
In 1716, The Czar Peter the Great ascended the corridor on horseback while visiting Copenhagen.
In 1902, a Beaufort car was the first motorised vehicle to ascend this Round Tower.
A medal in the Round Tower's collection of medals indicates that the first bicycle race held in the tower took place as early as 1888, possibly in connection with The Nordic exhibition of Industry, Agriculture, and Art.
In 1911, the newspaper Socialdemokraten arranged a bicycle race down the Round Tower.
In 1971, Ole Ritter won a bicycle race against Leif Mortensen up the Round Tower in a time of 55.3 seconds.
In 1993, Henrik Djernis won a bicycle race against Jens Veggerby in a time of 50.05 seconds.
In 1989, Thomas Olsen went up and down the Round Tower on a unicycle in 1 minute and 48.7 seconds, which is a world record.[6]