Where to find the chest Atherton's Cache

The chest is located in the Harrows region. As you progress through the story in this area, you will reach the Old Mill, and your starting point will be the Mill House hideout.

Exit the shelter and turn right, then go down the stairs and continue south until you reach a wall that you can climb down. Once down, follow the left side until you reach a place where you can jump over. Jump to the other side. To the left is a corpse next to Atherton's chest.

Where to find the key to Atherton's chest

The key to Atherton's chest can be easily missed. From the chest, go straight and jump to the other side of the road. Continue forward until you reach the shore of the beach.

Go down to the shore and you will see a broken wooden cart not far from you. Approach the cart and look for a small box. Take the key. Open the chest and pick up new equipment.