Overview
At the end of Slime Rancher’s adventure mode (and activating the credits), you will receive a message from Hobson Twillgers talking about the vaults. These (3) vaults contain Treasure Pods or Gold Slimes, which give A LOT of gold plorts.Each vault contains a Slime Door that requires a Slime Key to open. You will need to get the Treasure Cracker to Mk. III upgrade in order to open the Treasure Pods found in each vault.
All Vaults on the Map
Vault #1 – Ring Island (Dry Reef)
Notes: Pop the tabby gordo (shown below) on the beach islands, behind the overgrowth expansion.
A teleporter will appear, go through it to get to Ring Island.
Get to the highest part of the island, just follow the wooden pathways to the pink gordo. Jump over to the rocky steps on the side and continue to the higher ledge to find the vault.
VISUAL GUIDE (by crackedrabbitgaming): [link]
Vault #2 – Moss Blanket
From the start of the moss blanket:
head LEFT into the big area,
go RIGHT through the feral slimes,
go LEFT over/through the log,
instantly turn LEFT after you exit the log and go along the wooden bridge/path,
keep following the path and jump over the gaps,
head forwards over another log,
go LEFT past the hunter gordo/big mushroom,
follow the path and you will find the vault.
WARNING BEFORE YOU GO INTO THIS VAULT:
Gold slimes are going to spawn in this vault, there are food trees inside however I strongly suggest you bring food with you before opening the vault so you can feed the gold slimes.
VISUAL GUIDE (by crackedrabbitgaming): [link]
Vault #3 – Ash Isle (Indigo Quarry)
Pop the rock gordo shown below, after the gordo pops a teleporter will appear which will send you to the Ash Isle.
Head to the top of the island, and the vault will be through the right archway of the crystal gordo.
VISUAL GUIDE (by crackedrabbitgaming): [link]
Conclusion
For a visual walkthrough of where to find each Slime Rancher vault at the end of adventure mode, check out this video from CrackedRabbitGaming.
Now that you know how to find every vault location in Slime Rancher, make sure you upgrade your Treasure Cracker and have three extra Slime Keys handy before venturing off to each one.