Tucked away in a courtyard down Calle della Vida near Campo Manin you'll find a magnificent spiral staircase reminiscent of a snail (“bovolo”) as well as the Leaning Tower of Pisa. It was built in the 1400s so the Contarini family could show off. (Those Venetians.) You can climb up during the day or just admire from below. Another great way to see it is by moonlight: The marble seems to glow.