The fortress was a large facility in Haven City, featured in Daxter and Jak II, also making an appearance in Jak 3. It was located adjacent to the southern Slums and central Main Town, and served as the primary headquarters for the Krimzon Guard. It also housed the city's prison, as well as a large dark eco factory used for the Dark Warrior Program. Following the Krimzon Guard's reformation into the Freedom League, the fortress was re-painted from red to blue, and was presumably used by the Freedom League until inimical battle rendered the front door inaccessible.
Partway through investigating the palace, Daxter dropped in on an argument between Count Veger and Erol as to whether dark or light eco is "the key", Veger arguing that a map of the prison shows that five bar one prisoners have died as a result of dark eco poisoning, and Erol arguing that the surviving prisoner, Jak, is special, according to Onin. While Daxter stayed hidden, Tik inserted himself to cause a distraction, resulting in the prison map falling on the floor near Daxter. With it, Daxter was able to determine where Jak was located in the prison.
Shortly afterward, Daxter witnessed Kaeden harassing Osmo at the Kridder Ridder shop. The former proceeded to detonate the shop, Daxter then vowing to avenge Osmo but noting how he needed to rescue Jak and that he needed a plan. Ximon then lifted Daxter above the fortress in the company van, and dropped him down into the building. After encountering and evading numerous guard patrols, metal bugs, dark eco hazards, and other prison cells, Daxter found a monitoring room where he witnessed Jak being injected with dark eco.
Daxter thereafter encountered Kaeden, who revealed himself to be a giant metal bug leader. The final boss battle occurred and took place in two large chambers, one filled with dark eco and the other with light eco.[a] The fight ended in a control room at the bottom of a seemingly endless depth of the fortress. After Metal Kaeden's defeat, Daxter rode a levitation platform to the torture chamber and rescued Jak, seen in the opening cinematic of Jak II.
During Jak II, the fortress served as the place of the first mission "Escape from fortress": After Daxter found Jak, the duo traveled through the upper networks of the fortress, ending in the facility's drain, where Jak exited the prison from a high-up door. Jak later re-visited the fort in the mission "Blow up ammo at fortress", where he sabotaged one of the Baron's operations on behalf of the Underground. It is in this mission that Jak discovered the Baron's forces were trading eco with metal heads, witnessed when a couple of grunts met some guards at the entrance to the Haven sewers inside the fortress.
When Tess and Samos Hagai (both the Shadow and the Sage) were arrested and imprisoned at the fortress due to their connections with the Underground, Jak lastly visited the facility to free his friends ("Rescue friends in fortress"). Here he took out heavy patrols of guards, including the recently implemented elite guards and hover guards, and also evaded several laser-guided turrets and spydroids.
After Jak II, following the dissolution of the New Krimzon Guard and the creation of the Freedom League, the fortress continued use as presumably the Freedom League's fortress, but was heavily damaged from the ongoing war activity. The fortress' interior was inaccessible and not featured in Jak 3.
The main entrance to the fortress is situated along its eastern wall, located in the back of the southern Slums sector of Haven City. During Daxter, Daxter visited the underground levels of the prison, while in Jak II, Jak and Daxter visited the upper levels of the fortress.
When Daxter was first dropped into the prison, as it is called during this game, he landed in a corridor which preceded an underground service tunnel and was patrolled by a guard. After being chased by the guard on a service zoomer through the tunnel while dodging electrified fences, Daxter accessed several highly patrolled detention blocks with jail cells and storage rooms spanning four floor levels. These sections consisted mostly of either chambers with several jail cells along the walls, or sidescroller-style floor levels intertraversed via elevators.
Eventually Daxter crawled through a ventilation shaft which led him to a massive dark eco factory. The floors of these sections were completely flooded with dark eco, with pipes placed along the walls that pumped dark eco upward and downward. Daxter was able to cross these areas via the pressure boost attachment in combination with grated platforms, all while evading guard patrols and battling metal bugs. Daxter later entered a control room with several computer terminals, where he witnessed Jak's injection torture.
Past a large door in the back of said control room is where Daxter encountered Kaeden. The first stage was another dark eco factory similar to the ones witnessed before, though it eventually collapsed and was reduced to a large pool of dark eco, with only a few floating platforms for Daxter to land on. After Daxter drained the dark eco via heat-activated springs, Kaeden fled to the second stage, which was similar to the first but with light eco instead of dark, and had huge columns of the substance.[b] Upon being defeated, Kaeden crawled onto a small platform with several control panels. Here is where Daxter accessed a floating lift, which took him to the site of the injection chair in Jak II.
The fortress was the site of Jak's prison break, beginning in the primary injection chamber. This area consists of several jail cells along the perimeter of the room, strange ventilation shafts emitting a green gas, and a warp gate in the back. Most notable, however, is the presence of injection equipment in the center of the room. The equipment is placed on a platform above a computer terminal, and is situated in the middle of a seemingly endless depth, though as revealed in Daxter this depth is actually the location of another control room.
Ahead of two smaller rooms, the latter of which is filled with crates, bookshelves, and a locked door in the back, is a huge warehouse. The bottom of the warehouse serves as a parking lot for several security tanks, while the upper regions of this room, where Jak traversed, contains cranes, computer terminals, and service platforms. Ahead of this area is a control room with grated flooring, making Jak vulnerable to guard fire from below. Beyond this area is a small room with a destructible floor panel, which takes Jak down to a small maintenance corridor, at the back of which is another destructible floor panel. This panel is placed directly above a large chute which spits Jak out into a drain or sewerage area, flooded with water but also containing many stacked crates, allowing Jak to climb to a high-up exit door.
After this, the fortress is only accessible to Jak through the Slums entrance. The first area after this entrance has several computer terminals, an idle security tank, an entrance to one section of the fortress to the left, and an entrance to another section in the back, the latter two of which lead to two different missions.
After entering the entrance to the left, the alarm will be triggered and the security tank will activate. There are a few grated platforms around the following area, one of which is monitored by a number of laser-activated turrets. Just ahead of this is a large room with two columns, at the top of which are four arms ending in platforms that rotate about the columns' vertical axes. There is an electrified fence in the back of this room located up above that corresponds with tubes placed at the top of the columns. Past this fence is a network of corridors patrolled by several guards. This area has several conveyor-like platforms, computer terminals, stacked boxes, and grated walls. Beyond this is a large munitions room, with a large missile, several smaller rockets around it, more computer terminals, and another security tank. This room also contained a floor grate, through which another room with access to the Haven sewers can be seen but not accessed. After the missile explodes, the leftmost entrance back in the primary entry room becomes inaccessible due to wreckage.
Back in the primary entry room and past the previously-electrified fence in the back is a corridor guarded by several guards, elite guards, and hover guards. Past this area is another electrified fence which must be deactivated via large buttons atop several columns placed along the corridor. Beyond the gate is a control room monitored by several laser-activated turrets, with a half-pipe structure in the back that leads to a more elaborate control room. This area has four more turrets, several computers, a number of guards, and a grated ceiling through which guards will fire down at Jak. Past this is a small room with several shock-inducing spydroids, with a door in the back that leads back to the primary injection chamber.