Halo Array

The Halo Array is a group of massive installations made by the Forerunners to combat the Flood, a parasitic organism with an unstoppable appetite of all living things, and are key locations in the Halo games. There are a total of 7 Rings in the galaxy and one is capable of wiping out all live within a 10'000 Light Year range. The Covenant believe that the Rings are 'sacred shrines' and are the path to 'The Great Journey'. They also have worlds inside the rings for studying and containing The Flood. The array is controlled by The Ark, a structure that fired the remaining rings if one ring failed to fire.

Trivia:

 * Darkblade Crystalheart use the Rings as bases of operations rather than weapons.