Murialdo is a scattered commune in the upper valley of the Bormida di Millesimo, made up of several small villages -- Isola Grande, Piano, Ponte, Riofreddo, and Valle -- connected by narrow roads through chestnut and beech woods.
The parish church of San Lorenzo at Ponte dates from 1445. It was renovated in the baroque era, but the original Gothic facade in brick, with its pointed-arch portal, rose window, and campanile with three rows of two-light windows, survives largely intact. At the locality of Costa, the ruins of a medieval castle of the Del Carretto family include a keep, a long stretch of wall, and two gates with pointed arches.
The surrounding woods are rich in chestnuts and mushrooms, and the local economy still depends on agriculture, woodworking, and forestry. Murialdo is not a destination on its own, but a pleasant stop if you are exploring the inland valleys behind the Ligurian coast.