Page "Pillars of Hercules" Paragraph 4

According to Greek mythology adopted by the Etruscans and Romans, when Hercules had to perform twelve labours, one of them was to fetch the Cattle of Geryon of the far West and bring them to Eurystheus ; this marked the westward extent of his travels.

A lost passage of Pindar quoted by Strabo was the earliest traceable reference in this context: " the pillars which Pindar calls the ' gates of Gades ' when he asserts that they are the farthermost limits reached by Heracles.