In Greek mythology and later Roman mythology, the Cyclopes ( ; , "Kýklōpes", "Circle-eyes" or "Round-eyes"; singular Cyclops ; , "Kýklōps") are giant one-eyed creatures. Three groups of Cyclopes can be distinguished. In Hesiod's "Theogony", they are the brothers Brontes, Steropes, and Arges, who provided Zeus with 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.