How to open the arm door in Sons of the Forest

Sons of the Forest is filled with bizarre areas, strange mutants, and hungry cannibals. During your time on the island, you will be searching for a mysterious cube that is mentioned in a lot of the notes and even on some pamphlets that are laying around. The key to finding this cube and learning the story of the island is hidden by a mysterious door with a mark that looks like an arm on it. This guide will show you how to open the arm door in Sons of the Forest.

Where to find the arm door in Sons of the Forest

The arm door is located in a bunker on the eastern side of the island from where you spawn. It is indicated by a green dot along the coast of the island. This area is also south of where you can find the revolver. To open the bunker, you will need to get your hands on the maintenance keycard.

After reaching the bunker, head inside and take the stairs down. You will traverse down multiple flights of stairs and go through a few hallways until you find a room with a bunch of pipes and blood splattered on a glass wall. Head through the door on the far side and go left. Proceed down the hallway and you will enter a room with a bunch of paintings. Go through the door between the paintings.

At the end of the hallway, you will be in a living area. Head to the left and go through the door to enter the bedroom. Go right and you will find the bathroom. There is a destroyed wall in the bathroom shrouded by smoke. Go through the smoke and you will be in a cave. The door will be directly in front of you.

Related: How to craft the repair tool in Sons of the Forest

How to open the arm door in Sons of the Forest

If you find this door early enough in the game, you won’t be able to open it. This is because you lack the item required to interact with the door. To unlock the door, you need to get your hands on the Golden Armor. The Golden Armor is found within a bunker you can discover earlier in the game. This bunker will lead you to a cutscene where you see a large mutant that blocks the path you came from.

After progressing through the bunker, you will find the Golden Armor sitting on a couch past where you can find the katana. When you reach the arm door interacting with the door will open it, leading you to the final section of the game. Make sure you are prepared and have the cross on you.