In Greek mythology and later Roman mythology, the Cyclopes (/saɪˈkloʊpiːz/ sy-KLOH-peez; Greek: Κύκλωπες, Kýklōpes, "Circle-eyes" or "Round-eyes"; singular Cyclops /ˈsaɪklɒps/ SY-klops; Κύκλωψ, Kýklōps) are giant one-eyed creatures. Three groups of Cyclopes can be distinguished. In Hesiod's Theogony, the Cyclopes are the three brothers Brontes, Steropes, and Arges, who made for Zeus his weapon the thunderbolt. In Homer's Odyssey, they are an uncivilized group of shepherds, the brethren of Polyphemus encountered by Odysseus. Cyclopes were also famous as the builders of the Cyclopean walls of Mycenae and Tiryns.