The Atlantis biome is the hidden underwater zone added to Drain the Lake, and clearing its sealed door hands you a free Legendary reward. Getting there takes the right bucket, a randomized biome roll, and one short water puzzle. Everything below moves you from finding the biome to walking out with the Trident Bucket.
Quick answer: Equip the Jewel Bucket, reach a checkpoint past Checkpoint 5 where Atlantis spawns, drain the biome until the Jeweled Bowl appears, fill the bowl with the Jewel Bucket, then interact with the giant door to enter the chamber and claim the Trident Bucket.
What you need before entering Atlantis
Only one bucket works here. You need the Jewel Bucket equipped before you attempt the door, because it is the single bucket that can fill the Jeweled Bowl. No other bucket completes the puzzle, so swap to it before you start draining the biome.
The Jewel Bucket comes from a specific run outcome. Instead of taking the standard phone ending at the Abyss, skip it and reach the Angler Fish area ending. Finishing that alternate route is what unlocks the Jewel Bucket for future runs.
Where Atlantis spawns
Atlantis has no fixed location. The Atlantis update reshuffles the biome and checkpoint order every run, so no two runs share the same sequence. The one constant is that the biome can only appear on a checkpoint past Checkpoint 5.
Because the placement is randomized, Atlantis might show up right after Checkpoint 5 or much deeper in the same run. Some runs will not generate it at all. If it does not appear, the only fix is to start a fresh run and roll for it again.
| Condition | Detail |
|---|---|
| Spawn point | No fixed location; randomized each run |
| Earliest appearance | Any checkpoint after Checkpoint 5 |
| Guaranteed? | No; some runs skip Atlantis entirely |
| Required bucket | Jewel Bucket |
How to open the Atlantis door
Note: If the door stays sealed, the bowl is not full yet or you are not carrying the Jewel Bucket. Top up the bowl using the correct bucket and try the door again.
The Trident Bucket reward
Behind the door sits the Trident Bucket, a Legendary bucket you can pick up for free. Collecting it also awards the Lost Trident Badge, which pays out 150 Gems. That combination makes the puzzle worth completing every time the biome shows up.
Aside from the bucket and its badge, the chamber holds nothing else useful. You can explore the room, but there are no extra gameplay rewards inside.
Treasure chests and crafting materials
The ornate treasure chests scattered across Atlantis and inside the chamber are decoration only. They cannot be opened, hold no loot, and serve no gameplay function beyond setting the underwater scene.
Crafting materials such as Batteries and Generators do not come from Atlantis. Those drop from the wooden treasure chests found elsewhere across the lake, and whoever opens a chest first claims the materials inside it.
Because the biome roll is random, reaching Atlantis can take several attempts, but the path is always the same once you are inside. Drain until the Jeweled Bowl surfaces, fill it with the Jewel Bucket, open the door, and the Trident Bucket plus its 150-Gem badge are yours.
