The red door appears at all enemy encampments in Far Cry 3.
How to Open the Red Door[edit]
The door cannot be opened so long as the territory remains under enemy control. That problem's easy enough to fix though, isn't it? Simply head into the camp, dispatch all of the enemies, free the camp and the door will be yours for the plundering. Note that it does not matter which methods you use to free the camp, so long as the Rakyat can come in and liberate it after your work is done.
From now on, you can open up the red doors just like any other.
What's Behind the Red Door?[edit]
Behind the red doors, you will typically find a number of goodies. Along with a few standard environmental knick-nacks like beer crates, you will usually find a memory card and Ammo Vending Machine.
