On the northern side of the Ligurian Appennines, it consists of a number of settlements scattered over the upper valley of the Olba stream. Once a possession of the abbey of Tiglieto, it was donated to the bishop of Acqui in the eleventh century. Mentioned under the names of Urbs and Urba in the imperial diplomas of 981 and 1002, it shared the fortunes of Sassello, of which it formed part until 1798. The seventeenth-century parish church of San Giacomo, in the locality of Martino d’Olba, contains decorations and a marble altar from the eighteenth century. That of San Pietro d’Olba is a reconstruction from 1775. San Pietro d’Olba is a popular mountain resort with good hotel accommodation and various restaurants offering typical local cuisine. It attracts large numbers of vacationers in the summer and is famous for its excellent mushroom picking. There is also a local cottage industry producing furniture.