Leonardo studied the hills that encircle the basin of Florence, both as landscape elements and as observation points for the reconnaissance connected with the project for channeling the Arno. He drew their contours, evidencing the hills of Bellosguardo, Certosa, Fiesole, L’Incontro, Monte Ceceri, Monteoliveto, Montici and Il Paradiso. Leonardo visually surveys the scenario, fruit of an extraordinary blend of nature and artifice, in which he plans to intervene rationally; the ductus is that of the views from the Pisan Mountains, but with more aesthetic refinement and optical-perspective sensitivity, as in the vedutas en plein air of a traveller during the Romantic period.