Cengio is a small hill town in the Bormida di Millesimo valley, where the Ligurian Alps begin to flatten toward the Po plain. The nearby Cadibona Pass marks the geographical boundary between the Alps and the Apennines. From the 12th century Cengio was a fief of the Del Carretto family, who built a large castle; the Spanish attempted to take it in 1648 and destroyed much of the medieval fabric, and little remains beyond some ruins and the characteristic stone houses built against the valley walls.
The valley has been industrialised since the 19th century — proximity to the coast at Savona and abundant water made it attractive for manufacturing — but the town retains its old character. The surrounding forested hillsides offer walks through mixed woodland.
Cengio is about 30 km from Savona.