Round Tower.

Round Tower - the legend of Copenhagen.  It was she who, incidentally, is mentioned in the tale "The Tinder Box" by Hans Christian Andersen.  At the crown of the tower once upon a time there was an observatory, in which astronomers have studied the celestial mysteries.  Worked there and the great Tycho Brahe.  Round tower visited Peter I.  They say he climbed on top of the tower in one fell swoop, without dismounting from his horse.  While Peter's wife, Catherine I was even eccentric - she drove into the tower on the top three horses.