Italy's Venice is a city with many sights to see, but finding these sights can be difficult if you're not familiar with the town's address system. The city was built to make sense to those using the canals, not those on foot. You're bound to get lost at least once as you wander the streets searching for hidden gems of the city.
A map may tell you the name of alleys and squares, but a typical Venetian address is simply: San Marco 1323. Venice is split into districts called sestieri, and each building in a sestiere is numbered in one long consecutive sequence. Venice's random and informal street names are not officially part of an address, although many businesses will helpfully provide one. To pin-point a location therefore, you don't just need the brief official address, you also need a street/square name and also some helpful geographical pointer, e.g. a nearby church.
Even street names are far from straightforward. Most have evolved to describe an established location and mean descriptive things like 'Alley of the carpenters' or 'Courtyard with a well'. Consequently there are often several places with the same or similar names. If you are locating a street, you will require the name of the sestiere as well (what's more, sometimes there is more than one place with the same name in one sestiere). And even armed with official address, and street name, your task still isn't simple.
The next confusion is that sometimes one place may have more than one name. Even one name may have different versions - many streets in Venice are known both by their dialect name and by the Italianised version. Either of these may appear on maps. This is why you'll see many variations of placenames such as Fondamenta Nove (even throughout this website).
Streetsigns are not always easy to spot in narrow lanes. They may offer one or more variations on the name (o means 'or'), and they are often joined on the walls by signs identifying the parish (parocchia) and any adjacent canal (rio) or bridge (ponte).
If you're spending a long time in Venice or are just very interested in the city's structure, there is a good book called Calli, Campielli e Canali which provides extremely large scale street plans, along with property numbers. It covers Venice and the lagoon islands, and enables you to locate any address in the city, as well as providing some background information in Italian and English on landmarks and principal buildings. You can buy it in most bookshops in Venice. Sadly, it's rather too bulky to carry around as you explore.
What the names mean