London: Victor Gollancz Ltd, 1972. First U.K. Edition. First hardcover edition of Niven's best-known work, originally published as a Ballantine paperback original in 1970. "An exploration team consisting of an exotic mix of humans and aliens investigates a huge artifact [the Ringworld] occupying a planetary orbit around a sun. A novel of imaginary tourism; its real hero is the artifact, whose nature is further explored and explained in Ringworld Engineers (Barron, Anatomy of Wonder 4-392). A highspot of the genre, winning the Hugo, Nebula, and Locus awards in 1971. First Impression. Octavo (20.25cm); maroon paper-covered boards, with titles stamped in gilt on spine; dustjacket; [4],5-288pp. Tiny indentation to upper rear board edge, just a hint of foxing to upper edge of textblock, else internally fresh; very Near Fine. Dustjacket is unclipped (priced £1.90 net), with a faint wrinkle at upper spine panel, else a bright, Fine example.