Aside from being the centre of Locust society, not much is known about Nexus. No humans had ventured that deep into the Hollow until 16 A.E. when the COG initiated Operation: Hollow Storm, during which Gears tunnelled deep into Locust territory in what was meant to be a final counterattack against the Horde. Marcus Fenix and Dom Santiago of Delta Squad had ventured into the Locust stronghold in order to rescue several human prisoners, only to find them all dead or tortured past breaking point. The two explored Nexus and made their way to the Royal Palace in order to confront Queen Myrrah, the Horde's leader. During their exploration, Nexus was already under siege by Lambent forces, revealing to the COG that the Locust had already been fighting a civil war at the same time they had been conquering Sera's surface.
Nexus was destroyed when the COG triggered the collapse of the Jacinto Plateau, sinking their own capital in order to flood the Hollow with seawater in an effort to wipe out the Locust once and for all. Some Locust survived, however, and the flooding of the Hollow served to hasten the rise of the Lambent to the surface world.
The physical structure of Nexus was similar to a hive, and it is covered in bright yellow lights. The actual number of floors was unknown, but the structure appeared to have 15 "parts" when viewed from the outside. Nexus was suspended over a lake of Imulsion that protects it from subterranean threats. A series of turrets which surrounded the city provided additional security. A major highway served as the only entrance and exit to Nexus, and the pathway was utilized to deploy thousands of Locust troops at a time.
- Royal Palace - A central palace complex from which Queen Myrrah rules over the Horde.
- Pens - A series of "stables" for housing the Locust's Reaver mounts as well as other creatures such as Bloodmounts and Brumaks.
- Torture Yards - Areas where human prisoners were tortured or put to work as slaves.
- Imulsion Mine - A facility where the Locust gather Imulsion for fuel.