Java Edition Caves and Cliffs Part Two

1.18, the second release of Caves & Cliffs, is an upcoming major update to set to release in late-2021. It was first announced alongside the release of the 1.17 snapshot 21w15a.

Planned additions

 * Mountains
 * Height dependent generation.
 * Revamped, featuring some new small spruce trees on the slopes and ice and packed ice above the peaks.
 * Contain goats, rabbits, snow blocks, snow layers and powder snow.
 * Iron ore, emerald ore and coal ore are found in abundance.
 * Emerald ore no longer generates in veins of only one.
 * Can generate up to Y = 256.
 * New sub biomes Lofty Peaks, Snow Capped Peaks, Snowy Slopes, Mountain Grove, and Mountain Meadow.


 * Caves
 * Completely overhauled.
 * Now stretch down to Y = -59.
 * The cavern now generates in 2 layers of different stone bases depending on the depth.
 * Cavern layer above Y = 0 is made up of regular stone.
 * Stone transitions to deepslate from Y = 0 to Y = -7.
 * Deepslate now completely replaces stone from Y = -8 to bedrock.
 * Certain types of ores and structures still generate in the deepslate layer, as well as tuff.
 * Dirt, diorite, granite and andesite do not generate in this layer.
 * Biomes inside of caves introduced such as dripstone caves.
 * Contain aquifers, bodies of water with different heights, independent of sea level (Y=63).
 * Improved old caves to blend in with the new generations of caves better.
 * New carver called crack carver, which appears as a fissure on the ground, like ravines but narrower and can go very deep.
 * New noise caves, coming in 2 forms, cheese and spaghetti.
 * The original caves still exist, mixing with the noise caves.
 * Cheese caves have large stone towers stretching from the bottom of the cave to the top.
 * Very large, often large enough to fly with an elytra.
 * Abundant with aquifers and ores.
 * Spaghetti caves are long, thin caves that have small aquifers and are more similar to original caves.


 * Mineshafts
 * For support, if in the air, can generate with log pillars below or chains on fence posts above.


 * Strongholds
 * Try to generate fully encased in stone at low y-levels.

Biomes

 * Dripstone Caves
 * Contains pointed dripstone and dripstone blocks.


 * Lush Caves
 * Contain cave plants and moss.
 * Moss covers the ceilings and floors.
 * Clay pools generate inside.


 * Mountains
 * Come in 5 sub-biomes:
 * Mountain Meadow
 * The lowest layer of a mountain.
 * Contain flowers and sweet berry bushes.
 * Mountain Grove
 * The second lowest layer of a mountain.
 * Covered in snow, snow blocks and powder snow, and is filled with spruce trees.
 * Rabbits spawn in this biome.
 * Snowy Slopes
 * The second highest layer of a mountain.
 * Covered in snow, snow blocks, powder snow and ice.
 * Goats spawn only in this biome.
 * Lofty Peaks
 * The highest layer of a mountain, and will only generate if the mountain is high enough.
 * Generates if the surrounding biomes are too warm for snow capped peaks.
 * Covered in snow and ice.
 * Snow Capped Peaks
 * The highest layer of a mountain, and will only generate if the mountain is high enough.
 * Generates if the surrounding biomes are too cold for lofty peaks.
 * Covered in snow, snow blocks, powder snow, ice and packed ice.