The hideout was the primary headquarters of the Underground, located in the Slums during Jak II. Concealed behind a moving stone wall, it was located under ground beneath derelict apartments in a dead-end valley. Throughout the game, Jak would visit the hideout to receive missions primarily from Torn, but also the Shadow and Kor. The hideout served as the rebel movement's base of operations, and as such, the Slums sector was repeatedly targeted by Baron Praxis in hopes of damaging them, such as sending mobile bombs to the hideout, shutting off all water to that district, and deploying elite HellCat cruisers.
When the Underground militia merged with the New Krimzon Guard under Torn's former Krimzon Guard comrade Ashelin Praxis' governorship, the hideout was rendered unnecessary due to the move to the Freedom HQ when together they formed the Freedom League. The hideout can no longer be accessed in Jak 3, as the dead-end valley is blocked off by new apartments.
The interior of the hideout contained four sets of bunk beds on either side of the front room, then a deliberation table placed under a lamp further into the main room. Around the walls of the hideout were fireplaces, a suspended zoomer, boxes, shelving units, and various anti-Krimzon Guard posters. The entire area was protected with a small stone wall with an Underground emblem grafittied on.