The "Cattle of Geryon" refers to a herd of red cattle owned by the giant Geryon in Greek mythology. Geryon lived on the island of Erytheia, which was located in the far west. The cattle were known for their unique color and were guarded by a two-headed dog named Orthrus and a herdsman. The capture of the Cattle of Geryon was one of the twelve labors assigned to Heracles (Hercules). Heracles had to travel to Erytheia, defeat Geryon, and bring the cattle back to Eurystheus, the king who imposed the labors. This labor highlighted Heracles' strength and bravery.