This seems like a strange reason to go to Venice when you look at it from a surface view and has nothing to do with famed gondola rides, which are incredibly overpriced.
Venice is a city that has no cars, trains, or busses outside of the one train depot that brings you into the city. After that, there are only two ways to get around: old school walking or water busses, also known as Vaporetto.
At various docks throughout the city, you can catch a Vaporetto which will drop you off in the major areas of the city. The incredible aspect of this transportation, however, is the view. The majority of these routes travel down the Grand Canal, allowing you to take in the beauty of the city in the way you were supposed to see it.
If you take the correct Vaporetto route from St. Marks Cathedral, you can travel the outside of the city, introducing you to the various other islands in the Venetian lagoon and providing another, laid back, view of the city.
If you ever need a break after a long day of walking the city, a Vaporetto ride that shows you the beautiful architecture and makeup of one of the world’s oldest cities is absolutely the way to go.