Around 1502, during his travels at the service of Cesare Borgia, Leonardo noted on folio 94v of Ms. L the main stages of a trip through Tuscany and Umbria: "From Bonconvento to Casa nova 10 miles. From Casa nova to Chiusi 9 miles. From Chiusi to Perugia 12 miles. From Perugia to Santa Maria degli Angeli and then to Fuligno." This was, then, a distance of 19 miles in the Tuscan section, from Buonconvento to Chiusi. Based on the localities in this area appearing on map RLW 12278, the route could cross San Quirico d’Orcia to arrive, after about 10 miles, at "Casanova" in the Commune of the ancient Corsignano. In the second half of the 15th century this locality had undergone profound transformation at the initiative of Pope Pius II (Enea Silvio Piccolomini) who, seeing the degradation of his ancient hometown, had commissioned the architect Bernardo Rossellino from Settignano to rebuild it. This was the origin of one of the most beautiful "ideal cities " of the Renaissance, which was then named Pienza in honour of the pope.

From the city of Pienza it was possible to go on to Chiusi, passing in the vicinity of Monticchiello. But some doubts have arisen as to the reliability of Leonardo's cartography in this case. He represents Chianciano after Chiusi for instance, while in reality it is located much before it, towards Montepulciano; moreover, between Monticchiello and Chiusi he represents "Corsignano", indicating Pienza by its old name, but in a geographical position that seems more appropriate to the ancient stronghold of Contignano, in the Commune of Radicofani.