The petrographic and geochemical study of basalt blocks used in the foundations of the ancient city of Magna Graecia, Locri, proved that those rocks originated in Etna. They were not carried to Locri as building materials but were probably used at first as ship ballast before being utilized again for buildings. With a new approach, the Sicilian origin of those basalts corroborates the connection between Locri and Eastern Sicily, which connection has already been mentioned in historic sources. -- AATA