If you had the bad fortune of being imprisoned by the Doge, there is an "enhanced interrogation" room near the functionary archive. At night you would be brought here, have your hands tied behind your back, and hung by your arms. The window would let moonlight illuminate your face, while your interrogators sat in the dark, heard but not seen.

If you can manage narrow staircases, I strongly recommend the Secret Itinerary tour at Doge Palace in Venice