Ring-shaped artificial world with radius of 1 AU

An enormous artificial world that has a livable surface on the inside. Has a radius of about 1 AU so the inside surface has conditions like a livable planet. Centrifugal force keeps inhabitants firmly planted on the ring.

Examples

• 1970 Ringworld

  Perhaps the ur-example of this motif, Ringworld won both the Nebula in 1970 and the Hugo in 1971. Though not noted for its characters or plot, the technical aspects and fantastic concepts of this novel have made it one of the most influential 'Big Dumb Object' books. The Ringworld is an enormous megastructure built by unknown predecessors that features the livable surface of three million Earths, which is only partially scouted by the landing party.