By "Filetto", Leonardo indicates the castle of Filettole in the Commune of Vecchiano on map RL 12683 (Windsor Castle) and mentions it in the Codex Atlanticus (f. 305r).
The city, one of the most interesting in Tuscany as regards history and art, is represented on Windsor papers 12683 and 12685, and mentioned in the Codex Atlanticus (ff. 127 r and 305r). Leonardo mentions it already around 1487 on folio 64r of Ms. B, on which he draws some diagrams of bulwarks designed, according to a project by Brunelleschi, to flood the city. Although certain documentation is lacking, it is highly probable that Leonardo went to Lucca, where he would have visited such famous buildings as the Cathedral. It holds masterpieces of art such as the tomb of Ilaria del Carretto by Jacopo della Quercia, as well as splendid works by his contemporaries, among them the Tempietto by Matteo Civitali and the altarpiece by Domenico Ghirlandaio. It is not perhaps by chance that in Lucca and its surroundings we find, at a later age, numerous works by followers of Leonardo, with subjects ranging from the Last Supper to the Magdalene.
Molina di Quosa
By "Molina", Leonardo indicates Molina di Quosa, in the Commune of San Giuliano Terme, in the Val di Serchio.
Santa Maria in Castello
As reference point in the Valle del Serchio, on the right bank of the river, above a rocky spur overlooking Vecchiano, from the side opposite Pontasserchio, Leonardo represents and indicates the church of Santa Maria in Castello on map RL 12683 and mentions it in the Codex Atlanticus (f. 305r).
Leonardo indicates several times the Serchio river, which flows through the Communes of Bagni di Lucca, Barga, Camporgiano, Capannori, Castelnuovo of Garfagnana, Coreglia Antelminelli, Fosciadora, Gallicano, Lucca, Molazzana, Piazza al Serchio, Pieve Fosciana, San Romano in Garfagnana, San Giuliano Terme, and Vecchiano. He shows it on Windsor maps 12683 (in a position near the Bocca di Serchio) and 12277, in the Codex Atlanticus (f. 305r) and in Madrid Ms. II (f. 52v).