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Substratum introduces 14 distinct cave biomes that completely transform underground exploration. Each biome features unique terrain palettes, decorations, and atmospheric characteristics.

All Cave Biomes

Honey Grotto

Sweet caves filled with giant bee nests, flowers, and honey drips

Frozen Caverns

Icy underground chambers with massive icicles and snow coverage

Molten Passages

Volcanic caves with lava streams and charred terrain

Fungal Undergrowth

Earthy caves dominated by giant mushrooms and rooted dirt

Amethyst Hollow

Purple crystalline caves filled with amethyst formations

Subterranean Mesa

Underground badlands with layered terracotta patterns

Terracotta Caves

Colorful caves with rainbow terracotta stripes

Sandy Chambers

Desert-like underground caves with sand formations

Overgrown Dugout

Ancient caves overtaken by vines and cobwebs

Marble Mines

Pristine white caves with calcite formations

Granite Mines

Reddish caves featuring granite stone

Andesite Mines

Gray underground mines rich in andesite

Diorite Mines

Light-colored caves dominated by diorite

Coral Coves

Flooded underwater caves with coral reefs

Biome Characteristics

BiomePrimary MaterialsKey FeaturesColor Code
Honey GrottoMoss, Yellow Terracotta, HoneycombGiant bee nests, flowers, honey drips#EBCC31
Frozen CavernsSnow, Packed Ice, Blue IceGiant icicles, snow layers#91C9C4
Molten PassagesBlackstone, Black ConcreteLava streams, charred spikes#ED5D53
Fungal UndergrowthCoarse Dirt, Rooted DirtGiant mushrooms, cave grass#A37E77
Amethyst HollowAmethyst, Purple ConcreteGiant amethyst buds#BF85D6
Subterranean MesaRed Sand, TerracottaLayered terracotta patterns#B87218
Terracotta CavesRainbow TerracottaColorful striped patterns#664F37
Sandy ChambersSand, SandstoneGiant sand formations#BAB675
Overgrown DugoutCobblestone, MossHanging vines, cobwebs#222B23
Marble MinesCalcite, White ConcreteGiant calcite formations#F5EEED
Granite MinesGranite, StoneGranite veins#A77663
Andesite MinesAndesite, StoneAndesite veins#A6A898
Diorite MinesDiorite, StoneDiorite veins#E6E6E6
Coral CovesSand, GravelUnderwater coral reefs#033DFC

Vanilla Cave Biomes

In addition to the 14 custom Substratum biomes, the pack also includes three vanilla Minecraft cave biomes:
  • Lush Caves - Features moss, dripleaf plants, azalea, and glow berries
  • Dripstone Caves - Contains large pointed dripstone formations
  • Deep Dark - Dangerous caves with sculk sensors and shriekers (generates only between Y=-64 and Y=0)
These vanilla biomes are integrated into the cave generation system and spawn alongside Substratum biomes.

Generation Range

All Substratum cave biomes generate between Y-level -63 and 300 by default, with deepslate replacing stone below Y-level 7. Vanilla cave biomes (Lush Caves and Dripstone Caves) generate in the same Y-level range, while Deep Dark is restricted to Y=-64 to Y=0.
The scale and distribution of cave biomes can be configured via substratum_meta.yml. The default cave biome scale is 200 blocks.

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