Walking through the cathedral, almost on my way out, I saw a sign to visit the roof (left side). You can take the elevator up, and there is a metal construction on top of the roof so you can walk about a bit. It was a bit shaky and my fear of heights started to act up, but as the two elderly French ladies in front of me were moving up stoutly, I felt like I couldn’t stay behind either :). I’m glad I gathered my courage, the view was just great! Be sure not to skip this when you are visiting the cathedral.