The KG war factory is a large facility featured in Jak 3. It was used and operated by Cyber Errol during the War for Haven City to mass-produce KG Death Bots, and was suspended high into the sky above Haven City, looming over its citizens. In the game, Ashelin Praxis explained that they must shut down the factory but that it is shielded and has gate codes at every access point. She then sent Jak and Daxter to the power station, as that is where the old Krimzon Guard hid their access keys. Daxter was able to locate the cipher glyph, which Torn used to decipher the main shields. Afterward, Jak and Daxter were sent up to the KG war factory via the HellCat cruiser, destroyed the first lines of defense (during which they were met with fire from KG fighters and security tanks), and proceeded to infiltrate the factory.
The duo eventually reached the central control room where they confronted Cyber Errol. The KG leader explained to them that he had been communicating with the Dark Makers, and that he planned to destroy the planet. Jak battled him, during which Errol collaterally destroyed the factory. The battle ended in a wounded Cyber Errol escaping through a dark maker warp gate and the factory falling out from under the duo. During the battle, Cyber Errol utilized dark maker hornets and troopers, which confirmed Samos Hagai's suspicions that the factory served a purpose beyond just making death bots.
The war factory is a massive floating facility consisting of a rectangle base, a cylindrical tower in the middle, and a spire situated beneath it. At each of the corners of the rectangular base are the primary defense towers, with the actual production taking place at the "ground" level. This ground level contains various production lines, gates, conveyor belts, and other equipment, machinery, and scaffolding. There is also a production line for security tanks which appear to double as factory defenses. Located throughout the factory are also spawn pods for hover guards and spydroids. Cyber Errol's command center is located at the center tower, and consists of glass tiles, four spawn points from which roboguards and dark makers appear, and a balcony up top where Cyber Errol commands his forces. There is also the strange warp gate here located in the back of the room.
A small part of the factory is traversed by Daxter, who, because of his small size, was able to climb certain areas of the place to reach switches and open access for Jak. Another part of the factory was traversed via the factory car, which could bust through gates using its boost.
Because the factory is so high up, it allows for a bird's-eye-view of Haven City and as such reveals several things. The entirety of the palace ruins can be seen here, which reveals the exactness of the layout and the destruction of the Tomb of Mar. This view can also confirm that the strip mine, Mountain Temple, pumping station, and Dead Town (all locations from Jak II) remain in-tact. However, it also shows the Port with the layout from Jak II, instead of the change in Jak 3.
After completing the mission Beat Cyber Errol boss the war factory will still appear floating in the sky for the rest of the game on the PS2 version. However, after defeating Cyber-Errol in the Jak and Daxter Collection version of the game, the war factory will no longer be visible in the sky, but will reappear after completing the game.