Hercules, Pillars of

Twin rocks of Calpe at Gibraltar and Abyla at Ceuta which guard the western entrance to the Mediterranean Sea.

According to the Roman writer Pliny the Elder and the Greek geographer Strabo, Hercules tore apart the rocks which had before divided the Mediterranean Sea from the ocean. Another legend asserts that he forced the two rocks together to make a temporary bridge for the safe transit of the herds of Geryon to Libya; yet another says that he narrowed the strait so as to shut out the sea monsters which had previously made their way in from the ocean and infested the Mediterranean.