At Imbersago, in the northern part of the river, you can cross the river using a curious ferry-boat built after one of the drawings of Leonardo. The boat uses the current of the river with an moving submarine wing that, like a sail, pushes the boat across the river along a rope. The ferry can transport even cars. It’s not clear if Leonardo was the first to invent this boat, or if he drew it only because, like us, he was fascinated by the geniality of the idea.