Pillars of Heracles, two promontories at the eastern end of the Strait of Gibraltar. The northern pillar is the Rock of Gibraltar at Gibraltar, and the southern pillar has been identified as one of two peaks: Jebel Moussa (Musa), in Morocco, or Mount Hacho (held by Spain), near the city of Ceuta (the Spanish exclave on the Moroccan coast). The pillars are fabled to have been set there by Heracles (Hercules) as a memorial to his labour (one of the 12 Labours he was forced to do as penance for slaying his wife and children) of seizing the cattle of the three-bodied giant Geryon.