Era
On maps RL 12277, RL 12278, RL 12683 (Windsor Castle) and on folio 53r of Madrid Ms. II, Leonardo indicates several times, among the tributaries on the left bank of the Arno, the most important river in the Valdera. He mentions its position in relation to its confluence with the Arno on folio 22v of the same Madrid Ms., and, above all, on map RL 12279, describes the Valdera with a view of the hills on the right bank of the river, presumably seen from the height of Volterra. The course of the Era begins in the Commune of Volterra, flows for 55 km, has as its main tributaries the Cascina, the Roglio, and the Sterza, and traverses the Communes of Capannoli, Lajatico, Peccioli, Ponsacco, Pontedera, and Terricciola.
Fabbrica
Leonardo represents and indicates the stronghold of Fabbrica di Peccioli, on maps RL 12278 and RL 12683.