Pillars of Heracles.
     The tenth labor of Heracles (Hercules), the theft of the cattle of Geryon, took him to Erytheia, an island on the westernmost edge of the world. On this journey, Heracles erected two pillars—traditionally identified as the rocks of Calpe (Gibraltar) and Abyla (Ceuta)—at the Atlantic entrance to the Mediterranean Sea, so that future travelers could see how far he had come. Some sources call them the Pillars of Gades, referring to the Phoenician colony on the Spanish coast (now Cadiz), northwest of Gibraltar, close to where Erytheia was thought to be located. According to another legend, the rocks were originally one mountain range separating the two seas, which Heracles wrenched apart to create what is known today as the Strait of Gibraltar.

Further Reference:
Galinsky, G. Karl. 1972. The Herakles Theme: The Adaptations of the Hero in Literature from Homer to the Twentieth Century. Totowa, N.J., Rowman & Littlefield.

Listings for Heracles are arranged under the following headings:
; Birth of Heracles; Infant Heracles and the Serpents; Choice of Heracles; Madness of Heracles; Pillars of Heracles; Heracles and Cacus; Heracles and Antaeus; Heracles and Deianeira; Heracles and Iole; Heracles and Omphale; Death of Heracles; Apotheosis

See also Heracles, Labors of; Alcestis; Jason, and the Argonauts; Laomedon; Odysseus, in Hades; Pirithous, Wedding; Prometheus, Freed; Theseus, and the Amazons; Titans and Giants