They’re restoring the back side of the Palazzo Ducale and the corresponding side of the Prigioni Nove, both facing the Rio Canonica. The Bridge of Sighs connect these two buildings across the canal.
To get funds for the restauration works they have sold advertising rights to the façades being restored, and the sponsor have clad them in blue.
It makes a paddle down that rio an almost surreal experience, and even if the Bridge of Sighs is still visible, it just isn’t the same experience. On the other hand, we can hardly complain that the city is maintaining our common heritage.