Secret room location.
The secret room on Spire is a Halo: Reach glitch which can be done on the multiplayer map Spire. Using a camera, it is possible to get under the level. Once this has been done, a secret dark room is visible. The room is empty, except for a safety zone marker.
Gallery[]
Close up on the room. Notice the green "save area" emblem in the middle.
Sides of the room. Notice the transparency.
Close up on one of the sides of the room. With the save area, this suggests that the room is used during the campaign.