Octopath Traveler 0: All Crested Key Location

Octopath Traveler 0 scatters eight Crested Keys across its world, and you’ll need all of them if you want every legendary weapon. These weapons are some of the strongest gear you can get before the story’s final stretch, so collecting the full set of keys is absolutely worth the effort. 

Eight doesn’t sound like much, but with so many tucked-away NPCs and hidden dungeons, tracking them all down can take some work.

All Crested Key Locations

1. Your Starting Inventory

You can select the Crested Key for your starting bag when you first begin the game. It is not required, but it does save a bit of hunting later.

2. Viator (Valore Tavern)

Once Viator joins your party in Valore, he brings a Crested Key with him. More curiously, he only appears ready to join after you have already found a Crested Key somewhere in the overworld.

3. Mystery-Chasing Explorer (Sufraltajah)

Head to Sufraltajah and Entreat the Mystery-Chasing Explorer. He’s carrying one of the keys.

4. Black Market Merchant (Grandport Markets)

In the Grandport Markets, search for the Black Market Merchant and once more use Entreat. Again, he’ll hand over another Crested Key.

5. Young Antique Dealer (Victors Hollow)

The Young Antique Dealer in Victors Hollow also has a key, but you’ll need to obtain the key with the Purchase path action.

6. Sweltering Cave (Treasure Chest)

In the Sweltering Cave accessible only by Berecain Pass, you can find a treasure chest with a key inside.

7. Cyphlo Banks (Treasure Chest)

Another chest with a Crested Key can be found in the Cyphlo Banks, just over Donescu. You won’t have access to this area until you’re sent there during the early stages of the Bestower of Power storyline.

8. Outersea – Isle East (Shining Blue Spot)

On Isle East in the Outersea region, find a glowing blue pickup on the ground. It’s hard to miss—and it’s your final key.

What If You Didn’t Choose the Starting Key?

Which is kind of the big question hanging over completionists, because while the game hands you eight legendary weapons and insists eight keys exist, even accounting for the fact you can skip the starting one, the eighth should still be attainable. As it stands, the community suspects it’s tied to a town-upgrade reward, and that seems like the most plausible explanation.

How to Use the Keys – Isle of Heroes

Once you have at least one key—and Viator—you’ll see the Isle of Heroes appear on your Outersea map. Sail there, watch the cutscene, and interact with the tower door. A teleporter will zip you to the top, where a single boss fight awaits. It hits surprisingly hard, so bring a healer.

Once the battle is over, you are free to collect the legendary weapons at your leisure. The catch is that each Crested Key opens precisely one of these weapons; if a pedestal won’t activate, that simply means its key is still out there in the world.