The patron saint of Deiva Marina is Saint Anthony the Abbot, celebrated on 17 January. The town is divided into two main parts: the old town, towards the interior, which grew up around the square facing the parish church dedicated to him, built in 1730, and the Marina, a more recent area facing the sea.
The first hillside settlements, today's villages of Mezzema, Piazza, Passano and Caraschi, arose around the 8th century; it was precisely some of these «valley» inhabitants who, moving towards the coast in the following centuries, built the first village of Deiva near the sea. The whole area was long a fief of the marquises Da Passano, who built a castle in the locality of the same name and who, after submitting to the Republic of Genoa in 1144, became its allies and vassals; the Genoese republic incorporated Deiva and Mezzema into the podesteria of Moneglia and built two watchtowers there near the sea, one round and one quadrangular, the latter near the very church of Saint Anthony the Abbot.
