Altruist Camp

The Altruist Camp is the main headquarters of the Altruist Cult, situated in the heart of the Chiliad Mountain State Wilderness in San Andreas. It is almost completely isolated from the rest of civilisation, giving it a creepy atmosphere. The camp itself is made up of many wooden shacks surrounded by large walls.

The Altruists living here are hostile to any outsiders, except for Trevor Philips. However, after Trevor manages to kidnap enough people to bring to the camp, the Altruists will betray Trevor. This is a bad choice, as Trevor overpowers the cultists and eventually destroys the camp.

Events of GTA V
The Altruist Camp is not particularly featured in any storyline missions during Grand Theft Auto V, but certain characters involved in Strangers and Freaks can be kidnapped by Trevor to be taken to the camp. After he manages to capture five people, the cultists will suddenly turn hostile, and open fire on Trevor. He escapes, steals several weapons and cash, and burns down the camp. After the battle, the camp will be abandoned and in ruins.

Trivia

 * The Altruist Cult is one of two locations in GTA V where the player can encounter nudity. The other is the Vanilla Unicorn.