The Arno river made the history of Florence: it determined the birth of the city and its growth. Sometimes, it was unfortunately even the main cause of natural disasters. Florence is not built on Arno, but it is Arno that is inside the town, as it was decided in the Middle Ages to enclose the river within the city walls. In this way, it only would have been possible to exploit the water of the river best: for transportation and manufacturing. This tour is structured on the theme of water in Florence, it is one of the possible approaches to the history of the city, which will lead us to see the monuments of the town and other less known parts of it. Ponte Vecchio is a must, but we will take a look at other bridges of the town as well. There is much to know!