Corneo’s Secret Stash is a side quest in Chapter 14 of Final Fantasy 7 Remake.
Your task is to find out where Corneo’s Secret Stash key is located by finding Kyrie and then find all three secret stashes.
Here’s a walkthrough of Corneo’s Secret Stash in FF7 Remake.
To begin the quest, speak to the journalist Damon north of Sector 5 Slums.
Head to the Angel’s hideout
Next, head to the Angel’s hideout which is northeast from where the journalist is.
Inside the hideout, you will meet Mireille again. Talk to her and she’ll ask you to find Kyrie.
Also, pick up the note and you’ll learn where all the three secret stashes are.
Where is Kyrie?
Kyrie is located at the old church in Sanctuary Way. It’s the northern-most area you can go to in your map.
This part also coincides with the other quest Tomboy Bandit.
To get to the Sanctuary, you can fast travel (Chocobo) to Sector 5 Undercity Station first.
From there, just go through the gap in the gate.
Continue going all the way until you reach the old church.
You will meet Kyrie here. Remember to pick up the medicinal flowers near Kyrie as it’s used for another quest.
Talk to Kyrie and she’ll ask for your help to defeat a Shinra guy at the colosseum in exchange for Johnny’s wallet and the secret stash key.
Head to the colosseum
Go back to Wall Market’s colosseum.
Speak to the gatekeeper to begin the match. Choose special match.
Inside, you’ll face the Beastmaster again but this time he comes with a Hellhound.
Take them both out.
Return to Kyrie
Head back to Kyrie and get the key. Mireille reveals her true identity here.
Corneo’s secret stash locations
Once you have the key, you can find for the secret stashes.
If you look at the Corneo Vault Note you picked up earlier, you can see the locations given.
Collapsed Expressway stash
The first stash is at the Collapsed Expressway. The exact location is shown in the map below.
Use the key to open the door.
You will find some items inside, but this stash is the smallest of them all.
Steel Mountain stash
The second stash is at Steel Mountain, north of Sector 5 Slums.
It’s also nearby the Angel of the Slums’ hideout. The exact location is shown in the map below.
Likewise, open the gate with the key.
This is the biggest stash of them all. You’ll get plenty of items from both boxes and caches.
Sewers’ secret stash
The third and last secret stash is located in the sewers.
This one requires you to follow the main story (Intel). You have to follow Leslie to the sewers first.
To begin this part, you’ll need to visit the Don Corneo mansion at Wall Market.
Just follow the story until you reach the Old Trunk Line – Control Section which is very far inside. The exact location of the vault is shown in the map below.
Once you reach the area, you’ll notice that you can’t access the stash due to the water levels.
How to lower the water level
To lower the water level, you need to follow Leslie first. In the same map, he’ll go through a door and there’s a ladder inside the room.
Beside the ladder, there’s a console to lower the water level. The location of the console is shown below, marked by Cloud’s location.
Instead of following Leslie up, use the console first.
Go back to the vault and it’s accessible now.
Defeat the Sahagin Prince
Inside the vault, you’ll need to defeat a Sahagin Prince and two Sahagins first.
Once the enemies are gone, you can start looting the stash.
Give the stash to Marle
Once you’re done with all three secret stash vaults, return to Marle at the Park and give her the stash.
You’ll get The Art of Swordplay Vol. III as a reward.