There are a handful of Fish Ruins that you can find scattered throughout Abyss. These ruins have a lock on their door, preventing you from getting inside.

Here is a list of all the Abyss fish ruin locations, how to get their keys from the NPCs, and what rewards you can obtain.

To find the Fish Ruins near the Forgotten Deep, start at the edge of the dome next to Billy’s portable stash. Swim out ...