Zattere. It's a long and sunny walk along the Giudecca canal, protected during winter time from cold northerly winds for being exposed to south and shielded by buildings. You might find interesting to see how a gondola is made, stopping by the Squero (Venetian for small ship yard) across the canal near San Trovaso Church. It's one of the few still in business in town. With some luck, you'll see some gondole through various manufacturing steps