Abyss Gravel Walls are backing walls that are naturally generated in the Abyss. Naturally-generated walls cannot be destroyed or collected and spawn water in front of them whenever a nearby tile updates. Safe versions of Abyss Gravel Walls can be crafted from Abyss Gravel, which have the same appearance but do not release water.
- The walls' own water generation counts as a tile update for adjacent walls so that they generate water as well. This may lead to a chain reaction, which is useful for filling sections of the Abyss that may have generated without water.