One of the four wonders of the Square of Miracles, this unoficial symbol of Pisa is an all white marble freestanding bell tower that looks like a big thin wedding cake.It costs a pretty penny, to do so, but you can climb the tower that currently stands with a nearly four-degree lean – just be careful it doesn't tip over! We don't think it's so necessary to climb it, since it's free and beautiful to admire from the ground, but if you do want to venture up the tower, avoid disapointment by booking your tickets in advance.