A commune in the valley of the Bormida di Millesimo, it extends over the northern slope of the Ligurian Alps, which commence at the nearby hill of Cadibona. From the twelfth century it was a fief of the Del Carretto family, who built a large castle there. The Spanish tried to take the town, destroying the manor in 1648, and it was annexed to the kingdom of Sardinia in 1735. All that is left of the medieval part, which must have been imposing, are a few ruins. The houses huddled against the rock walls of the Salto are characteristic. Its proximity to the coastal region of Savona and the abundance of water have led to the development of manufacturing activities, resulting in a contraction of the agricultural sector, now confined to forestry (sawmills) and the cultivation of cereals.