The Cavern layer is the largest layer, beginning just below the Underground and extending down until the Underworld layer. Darker stone background tiles characterize it. Stone is the predominant block in this layer (as opposed to Dirt in the Underground). Caverns contain occasional Underground Cabins where valuables can be found, as well as Glowing Mushroom biomes, dangerous traps, rare and dangerous Spider Cave mini-biomes, and much more.
In large worlds, lava begins to appear around -2100ft in small pools, which gradually become lava wells at around the -3000ft mark.
|Map Size||Min Start Depth||Average Start Depth||Max Start Depth|
|Small||120 ft||480 ft||840 ft|
|Medium||180 ft||720 ft||1260 ft|
|Large||240 ft||960 ft||1680 ft|
- Spawns from Mother Slimes
NPC happiness 
|Underground / Cavern / The Underworld|
For more information, see NPC happiness.
This content is transcluded from Biome backgrounds § Cavern.
- Desktop 22.214.171.124:
- Desktop 1.3.2: Geysers now spawn as traps.
- Desktop 126.96.36.199:
- Desktop 1.2.2: New "Alternate Underground" soundtrack.
- Desktop 1.1: Random traps added.
- Desktop-Release: Introduced.
- Console-Release: Introduced.
- Switch 1.0.711.6: Introduced.
- Mobile-Release: Introduced.
- 3DS-Release: Introduced.