What inspired Halo's ring?

In 2006 Bungie published a list of the team's favourite science fiction on its own website, acknowledging that Halo's ring-shaped megastructures followed concepts in Larry Niven's Ringworld and Iain M. Banks' Culture series, with two Banks novels named as particularly influential: Consider Phlebas and Excession. Niven's ring is a band around a star, a million miles wide; Banks' orbitals are smaller, inhabited rings turning in space. Halo's ring sits between the two ideas, a weapon built like a world.

Designer Jaime Griesemer clarified what the borrowing actually was, in an Edge retrospective: 'The influence of something like Ringworld isn't necessarily in the design, it's in that feeling of being somewhere else. That sense of scale and an epic story going on out there.' He also named a third book for the other half of the game: John Steakley's Armor, a main inspiration for the soldier's story, 'a soldier has to constantly re-live the same war over and over again.' The ring gives the scale; Armor gives the Spartan.