From Halopedia, the Halo wiki
This article is about the multiplayer map. For the conference room on UNSC Point of No Return known as The Cage, see Odin's Eye.
The Cage is an asymmetrical map built into the Lagoon area of Forge World. It is reminiscent of Lockout from Halo 2 and Blackout from Halo 3, but retains its own unique layout. It is roughly the same scale as Lockout and is built around an open center, but features longer sight lines and paths that are strictly one way.
Note: These names are unofficial and are being used as a map directory.
Uncaged adds a few new walkways, most notably allowing faster access from the cliffside to the central area.
During the development of Halo: Combat Evolved, The Cage was the name given to the predecessor of what would come to be Lockout in Halo 2, albeit changed heavily. The Cage in Halo: Reach was designed using some of the original pre-Lockout layout ideas, and originally built on the original version of Forge World, which was based in a New Alexandria skyscraper, with the working name "Blockout". Following the revamp of Forge World into the map known today, designer Chris Carney was challenged by other employees to build a full map just using the Forge tools to prove it could be done. Carney did a week of design on paper, before moving into Forge to construct the map. Originally, the elevated section of the map was to be situated next to the cliff, but this was instead turned around to provide the players a visual reference point for where they are on the map, alongside the addition of a Forerunner spire and a blinking red light.