Already in use in the first half of the 19th century, it connected Sassa and the area of Val di Sterza with the territory of Castagneto Carducci, crossing the Gherardesca hillocks and descending towards the area of Bolgheri at Castagnolo, a place-name referring to the past activity of chestnut cultivation. On this stretch, at Fornacine, remains of stone kilns can be found among the vegetation.