A map of the Valdichiana

This is Leonardo’s most carefully finished map, centring on the long marshy lake that once occupied the Valdichiana in southern Tuscany. North is to the left, the Tiber runs along the top edge, and the southern bend of the Arno is at centre left; Arezzo is at upper left, Perugia at upper right, and Siena lower centre. See also RCIN 912682. The purpose of the sheet is not evident, though it must have been made for someone else to see. Leonardo was employed by the Florentine government on several projects in civil and military engineering, and it is probable that the map was made in connection with a plan to drain the malarial marsh, a field in which Leonardo clearly attained some reputation. Text adapted from Leonardo da Vinci: A life in drawing, London, 2018