Of course, there are enough people here who have described the castle. Here I am talking about the castle tower:
"Perhaps the most original and most elegantly proportioned creation of Karlsruhe classicism is the helmet of the castle tower, with which Wilhelm Jeremias Müller crowned both his work and the residence in 1785. Ten years after completing the extensive reconstruction of the castle, which was still carried out in the Baroque style, he had the curved hood of the old, disproportionately high castle tower removed and built a new dome-like roof structure with a balcony and lantern on the remaining tower shaft. Müller was a master at seamlessly matching the design of the tower helmet to the overall appearance of the castle.
The tower structure is also a textbook example of successful proportions. Its harmony arises primarily from the fact that Müller - consciously or unconsciously - applied the rule of the "golden ratio". This states that two lines are in an ideal relationship to one another when the larger line is to the smaller as the sum of both is to the larger. It is the same here: the height of the dome to the height of the lantern is the same as the total height of the lantern to the height of the dome.
The castle tower is open to the public via the Baden State Museum."
("City Walks in Karlsruhe - Classicism", book by Friedemann Schäfer)