Ringworld

Set in 2855, 'Ringworld' follows the story of Louis Wu, a 200-year-old human, Teela Brown, a young woman with extraordinary luck, Nessus, a Pierson’s Puppeteer, and Speaker-to-Animals, a Kzin ambassador.

They embark on a hazardous mission to explore the Ringworld, an enormous rotating ring with a habitable inner surface equivalent in area to approximately three million Earths.

The novel combines hard science fiction with imaginative concepts, including the Ringworld's artificial gravity, shadow squares for night and day, and advanced technologies like hyperspace travel and impact armor.

Despite some dated social attitudes and scientific inaccuracies, 'Ringworld' is a classic in the science fiction genre, known for its monumental sci-fi creation and influential ideas.