In Castello, not far from Piazza San Marco, you'll find the church of San Giorgio dei Greci - a Greek Orthodox church with a rich history. She stands as evidence of a once thriving Greek population within La Serenissima. One census taken in the 15th century indicates that there were about four thousand Greeks living in Venice. And while the Greek contingent in Venezia may have dwindled over the last few centuries, the church and her campanile still stand as a constant reminder of one part of Venice's diverse past.
The most noticeable thing about San Giorgio dei Greci is her campanile, which leans to the west, almost as if bowing to Piazza San Marco's much taller tower.
Many belltowers lean, in fact I once heard someone claim that Venice had more leaning towers than perfectly vertical ones.
Some have a more obvious tilt than others.
I've also heard that many of the belltowers of Venice have already come down. The ones left are the survivors. By some exaggerative estimations, Venice used to be crowded with campanile, bristling with belfrys.
This one also appears to have a more extreme lean because it hangs out over a canal (the Rio die Greci) and is easily seen from the Bacino San Marco and anyone walking along the fondamente Riva degli Schiavoni.
The tower was built in the late 1500's. It lists to one side due to uneven subsidence beneath.
The next time you're on a Vaporetto east of the piazza, find the Rio dei Greci and see if you can spot a "campanile with a cant".