Every tourist discovers immediately how unusual is Venice, the only major Italian city entirely on water. Many cities have rivers running through them, or lakes or oceans at the edge. But in Venice, you travel by water. In the warren of narrow streets, the commonplace advice is apt: Allow yourself to get lost! You are always near water, whose optical qualities are constantly changing with the weather and thanks to passing boat traffic. As Paul Hills observes: “No city built on land can offer so brilliant and so strange an intermingling and intensifying of the color of the sky and the color of the buildings on the surface of its thoroughfares.” “It is one thing to walk past a building,” Adrian Stokes wrote, “another to slide past, to slip slowly in a continuous movement.” Indeed, even looking out your window is a novel experience, as Jean-Paul Sartre noted: “The water is too well-behaved: you don’t hear it. Growing suspicious, I lean out: the sky has fallen in there.”