"The Ringworld" is a science fiction novel by Larry Niven, published in 1970. It explores the concept of a massive artificial ring structure that orbits a star, providing a habitable environment for its inhabitants. The story follows a group of explorers, including a human, a Kzin, and a Pierson's Puppeteer, as they journey to investigate this extraordinary megastructure. The Ringworld itself is about 1.6 million kilometers wide and has a circumference of over 3 million kilometers. It features diverse ecosystems and climates, making it a unique setting for the characters' adventures. The novel raises questions about technology, civilization, and the nature of intelligence.