The Grotte di Toirano, about 4 kilometres north of Ceriale, are among the most interesting prehistoric caves in Liguria. The cave system runs deep into the limestone hills and contains stalactites, stalagmites, and — more unusually — the bones of cave bears that sheltered here during the Pleistocene, as well as traces of human occupation stretching back tens of thousands of years.
Guided tours run through two main caves: the Grotta della Basura (Cave of the Witch) and the Grotta di Santa Lucia Inferiore. The first is the more dramatic, with its chamber of bear skulls and ancient handprints preserved in the clay walls. Tours last about an hour and are offered daily except Mondays. The caves maintain a constant temperature of around 16°C, making them a pleasant visit even on the hottest summer days.