This page of the guide to Biomutant contains a walkthrough of the Old World Storage side quest. Here we have described all the treasure vaults you must explore to complete the quest and earn rewards.
Starting the quest
How to get started: Reach one of the vaults.
Reward: Equipment acquired during vault exploration.
To start the quest, you must reach one of the vaults available in the game world. A key is required to open the vault.
Old World Storage 6I
Location: Fluff Hulk Nest
How to get the key: Defeat the Fluff Hulk.
The entrance to the vault is located at the top of the mountain, in a small hollow. You can simply walk there and use the key to open the door.