The main spiral staircase of Haut-Koenigsbourg castle was added in the 20th century during restoration work. Some said it was not accurately faithful to the Middle Ages and looked more like the Renaissance. It serves the three floors and the twenty-two rooms of the castle. The turret of the staircase, octagonal in shape, has openwork and decorations. With a total cost of 2,250,000 marks, the work was completed seven years after the laying of the first stone. The castle was inaugurated on May 13, 1908, in the presence of Emperor Wilhelm II.