Here it's how the Ponte dei Sospiri (Bridge of Sighs) looked like when we found it (I totally forgot it was right behind the Palazzo Ducale and I searched for it on all maps in vain...).
It's the link between the Palazzo and the prison, and Its name comes from the idea that the condemned were supposed to see the light of the day for their last time in their life through those windows.
The wrappers for the restoration works made it poetically look like suspended in the sky. The writing you see below the bridge means Sky of Sighs.