When classical Greeks looked at the ruined walls of Mycenae and Tiryns — fortifications built centuries before their time, with boulders so huge no team of men could move them — they decided only the Cyclopes could have raised them. The word cyclopean survives as architectural shorthand for stones beyond human scale.
In the Odyssey itself, it’s the cave of Polyphemus on the island of the Cyclopes that earns the term. Odysseus and his men stumble into a hall built for someone monstrous, with a doorstone that twenty oxen couldn’t shift. The whole episode runs on that scale-shift: men inside an architecture not built for men.
It’s the visual signature of the world before: massive, weathered, made by hands or eyes that aren’t yours.