Lying along the ancient road that led from the Oneglia coastline to Piedmont over the Colle di Nava, this little centre is situated in a splendid panoramic position overlooking the Maro Valley. It is not far away from Colle di San Bartolomeo (620 m.), which leads into the upper Arroscia Valley, and the Ginestro Pass (677 m.), which looks out onto the territory of Albenga. Because of its strategic position, Cesio was for centuries an object of contention between influential families: the Clavesanas and the Dorias and later the House of Savoy.

The ruins of the mediaeval castle in the municipal district of Cartari are remaining signs of these long struggles. In 1800, Cesio was the site of a bloody battle in which the Austrians defeated the French and forced them to retreat towards Nice.

The old town centre does not have any monuments of great importance, except for Baroque parish church of Santa Lucia, while the church and oratory in the district of Arzeno d'Oneglia have one very unusual feature: they share the same stone bell tower (perhaps originally a watchtower) which is divided by a central portico.The territory is divided between the olive groves and vineyards of the lower terracings and the woods (mainly chestnut, pine and oak) that climb up towards the mountain ridge, which reaches an altitude of 989 metres at Pizzo d'Evigno, beyond the municipal territory.

The olives that grow here are Taggia olives, one of the best kinds cultivated in the province of Imperia. The beauty of the landscape makes Cesio a favourite holiday spot offering many possible points of departure for excursions: to the woodlands of Cartari and the pine wood, San Bernardo di Conio and Pieve di Teco.