The weapons factory is a location featured in Jak II. It was a "secret" weapons facility, used by Krew and Baron Praxis to develop weapons, namely the piercer bomb and prototype roboguards. It is a tall building, situated on the small island that is home to the dig site and landing pad, neighboring the pumping station island. Jak visited here in Jak II after being given a top-level security pass by Ashelin Praxis under the directive to intercept a meeting between the Baron and Krew, the former of whom planned to use the developing piercer bomb to crack open the Precursor Stone.
During the mission, Jak was at first was met with resistance from guards and roboguards, but eventually reached the top and confronted Krew. After refusing to ignore the Baron's intentions, Jak proceeded to battle Krew. After significantly harming him, he received the Heart of Mar and escaped via HellCat cruiser transport from Ashelin, shortly before the bomb at the top of the factory exploded. Although the lower-levels of the factory are still accessible afterwards, the facility was never indicated to have returned to service and was seemingly replaced by the floating KG war factory during the War for Haven City.
The weapons factory is a large facility located on the island neighboring the pumping station, across from the dig site's elevator. It is met with a staircase leading to a door which requires "black" clearance. The inside is structured primarily with stone. Its primary features are all of the large pools, reservoirs, and pipelines carrying an acidic green sludge, presumably by-product of the experimentation, or fuel for the experiments themselves. The facility is traversed via various conveyors, which are usually switched in direction via a red/blue target, as well as track-guided bridges, capable of changing location via large bolt cranks. Other platforms are also used to traverse the area, such as those which have a target on them for being shot down.
The area contains a variety of defenses and hazards. The fast-moving conveyor belts present the danger of accidentally falling into the toxic sludge. Its primary defenses are guards, which use rifles to shoot at Jak from a long distance; sometimes they are behind an electric fence or high up on a ledge (the former of which has to be deactivated in order to reach them), making them hard to be disposed of and hard to avoid when in large number. Roboguards are also used as a defense, but are dispersed from opening hubs, and come in waves.