Designed by the architect Rangone, this unique staircase winds through the round tower. It starts with a single flight of stairs and then splits into two as it reaches the round tower. Originally, there was an exit leading to the park, but it collapsed during the earthquake of 1889. After that, the staircase was rebuilt inside to give the castle a more medieval feel.

Look at how the double flight of stairs leads to the upper floors, specifically to the entrance of the Portrait Gallery. It's amazing how such a grand and airy effect was achieved in a small space.