You have not truly visited Venice without seeing Rialto bridge. It is one of only a few bridges over the Gand Canal and by far the largest and most famous one. After 10 am the bridge starts to be crowded by tourists, so go early. We had a hotel close to the bridge, thus no problem. The water bus next to the bridge is also named 'Rialto' - so its easy to find, best take line 1.