Caves & Cliffs

Caves & Cliffs is the name for a major update that will be released for most versions of Minecraft, likely as Java Edition 1.17 and Bedrock Edition 1.17.0. It was announced in Minecraft Live 2020. It will include new cave and mountains features, as well the glow squid, a mob that was voted for during the third Minecraft mob vote.

Planned additions
Please note that the names of many features are conjectural.

Blocks

 * Azalea Leaves.png Blooming Azalea Leaves.png Azalea Leaves
 * Part of a new exclusive tree marking lush caves


 * Azalea Roots.png Azalea Roots
 * Part of the Azalea tree
 * Looks like a colonized by roots dirt block


 * Amethyst geode block.png Amethyst Geode
 * Generates amethyst crystals on top given time
 * Unobtainable in survival, and probably cannot be moved with pistons
 * Extremely rare, only generates in amethyst geode structures


 * Amethyst crystal cross.png Amethyst Crystals
 * Grow on top of geode blocks over time
 * Makes a jingling noise when walking over them
 * Break to produce a crystal shard item
 * These can be crafted into telescopes


 * Copper Ore.png Copper Ore
 * New ore, found underground.
 * Drops itself when broken, like other metal ores.
 * Spawns in new large ore veins.
 * Can be used to craft a Lightning Rod or a Telescope.


 * Block of Copper.png Block of Copper
 * Block of Copper Age 1.png Block of Copper Age 2.png Block of Copper Age 3.png Develops a patina of pale green copper carbonate over multiple stages, which might be sped up by weather such as rain.


 * Copper Stairs.png Copper Stairs
 * Copper Stairs Age 1.png Copper Stairs Age 2.png Copper Stairs Age 3.png Develops a patina of pale green copper carbonate over multiple stages, which might be sped up by weather such as rain.


 * Copper Slab.png Copper Slab
 * Copper Slab Age 1.png Copper Slab Age 2.png Copper Slab Age 3.png Develops a patina of pale green copper carbonate over multiple stages, which might be sped up by weather such as rain.


 * Restoring clay pots.png Clay Pots
 * Ceramic Shards can be incorporated into an unfired pot
 * Can be fired by lighting fire under the pot


 * New Vine.png New Vine 2.png Spore plant
 * Light source
 * Grows edible glow berries.


 * Spore Blossom.png Spore Blossom
 * Sends particles downward


 * Dripleaf Plant.png Dripleaf Plant
 * A plant that can be used for platforming
 * If the player stands on top of the plant for a period of time, the player falls through the plant


 * Baby dripleaf plants.png Small dripleaf plant-like blocks
 * Appear highly varied in models


 * Unidentified foliage object.png Unknown foliage block, possibly Moss
 * Looks grassy on all sides and opaque


 * Foliage carpet.png Unknown foliage carpet
 * Same texture as the above unknown block, but one pixel thick


 * Roots bloody roots.png Unknown hanging roots block
 * Seen in the distance of a lush caves biome, behind a spore blossom


 * Baby azalea tree.png Baby blooming azalea tree.png Small versions of azalea trees or azalea bushes
 * May or may not be saplings


 * Sculk Block.png Sculk Block


 * Generates in the Deep dark biome


 * Sculk Something.png Sculk Chute


 * Generates in the Deep Dark biome


 * Sculk Growth.png Sculk Growth
 * Generates in the Deep Dark biome
 * A layer that generates on top blocks like snow
 * Some have parts are transparent allowing the player to see the block it is on top of


 * Sculk Sensor.png Sculk Sensor
 * Generates in the Deep Dark biome
 * Can be used for wireless redstone
 * Senses block placement, footsteps, or projectiles
 * Wool can occlude its ability to sense
 * Can be used with a piston to create a wireless redstone clock


 * Stalagmites.png Stalagmite
 * Can be found in the new dripstone caves on the floor
 * Deals damage when landing on


 * Stalactites.png Stalactite
 * Can be found in the news dripstone caves on the ceiling
 * Can fall, probably damaging entities
 * Drips water, which can fill cauldrons placed below it


 * Unknown speleothem block.png Unknown block associated with speleothems

(possibly Dripstone, based off of the name of the biome which it is found in)


 * Appears to be made of the same materials as stalactites and stalagmites, but as a full cube.


 * Lightning Rod.png Lightning Rod
 * Crafted with copper
 * Redirects nearby lightning strikes to the top of the rod, which can prevent flammable structures from catching on fire during thunderstorms.


 * Powdered Snow
 * Deceptively similar to snow, but entities fall through it. Likely related to the "snowier snow" announced when the Mountains won the 2019 biome vote.
 * This is how regular snow layer blocks worked in old versions of Minecraft, but it was changed because it created accidental booby-traps when lava ponds generated at the right height to cut out the ground but not the snow.


 * Unidentified Stalagmite Torches.png White candles.png Candle-like blocks
 * Can be up to four in a block, similar to sea pickles
 * Can be black or white
 * Emits fire particles


 * Unnamed Stone.png Unknown grey stone block
 * Can be found around the deep dark cave biome walls
 * Can be found in huge groups


 * UnknownWhiteStoneBlock.jpeg Unknown white stone block
 * Similar to Diorite, but with a smoother texture
 * Found underground surrounding the outsides of geode formations


 * Clay or not.png Unknown whitish block
 * Found in lush caves
 * Might just be clay or sand, although its texture does seem different

Items

 * Amethyst Shard
 * Drops from Amethyst Crystals
 * Used to make telescopes


 * Axolotl Bucket JE1.png Bucket of Axolotl
 * Obtained by using a water bucket on an axolotl, similar to cod, salmon, pufferfish, and tropical fish
 * In demo had no name, showing its translation string "item.minecraft:axolotl_bucket"


 * Brush.png Brush
 * Used to carefully sweep away debris from archaeological items
 * Removes one pixel of height from the dirt or gravel block it is used upon each use
 * May allow for the creation of dirt and gravel layers and previously unobtainable block heights
 * There is also a blue variant: Brush 2.png


 * Bundle.png Bundle full.png Bundle
 * Can contain 1 stack of any item
 * Items are added by dragging bundle to an item
 * Tooltip shows icons of contained items
 * Items drop to inventory when right clicked


 * Blue Ceramic Shard.png Orange Ceramic Shard.png Ceramic Shard 1.png Ceramic Shard 2.png Ceramic Shard 3.png Ceramic Shards
 * Obtained with brush at archeological sites
 * Come in different colors and different designs, each depicting a different picture, such as an ender dragon, Alex, a skeleton, a tree and a grey skinned humanoid (possibly an Illager)
 * Can be placed/customized on clay pots


 * Glow Berries
 * Can be eaten


 * Telescope.png Telescope
 * Crafted from crystal shards and copper
 * When held, allows the player to see far away in a small circle

Mobs

 * Axolotl.png Axolotl
 * Small mexican salamanders found in bodies of water within the Lush Caves
 * Can be caught in a bucket like fish
 * Can be tamed with a fish
 * Come in different colors (Albino, yellow, green, brown, and purple/pink)
 * Plays dead when damaged to regenerate health
 * Attacks drowned, guardians, elder guardians and other fish.


 * Glow squid


 * Originates from Minecraft Earth
 * Glows in the same way that magma cube cores, blazes and the eyes of spiders, drowned and endermen do.
 * Lives in underground lakes.


 * Goat.png Goat


 * Spawns in mountains biomes
 * Can jump very high into the air to avoid obstacles
 * Attacks close animals and knocks them very far away
 * There is a baby variant and therefore presumably a way to breed them


 * Warden.png Warden


 * Spawns in the Deep Dark biome
 * Attacks the player when they sense movement
 * Follows sources of noise such as snowballs hitting blocks
 * Seems to follow the same rules as the skulk blocks when detecting noise
 * Will not detect players that are sneaking
 * Incredibly strong ( damage)
 * Has at least 85 health points
 * At least as fast as a player's walking speed
 * Likely spawns in relation to the hut seen in the clip
 * Seems to get faster when attacked

World generation

 * Lush caves
 * Generate below Azalea trees
 * Contain glow berries


 * Mountains
 * Revamped
 * Contain powdered snow and goats


 * Deep Dark
 * New biome at the "deepest depths of the world"
 * Warden is found inside
 * Contains the unidentified stalagmite torches
 * Contains Sculk blocks, a new block which responds to sound


 * Dripstone caves
 * Contain stalactites and stalagmites


 * Cave generation
 * Revamped to generate bigger, more adventurous caves.


 * Amethyst geode
 * A tiny underground cave-like feature
 * Contains geode blocks and the amethyst crystals they generate
 * Bell-like sounds can be heard here - whether a block emits these or if it's a biome thing (like the exclusive ambience for nether biomes) is unknown


 * Archaeological Excavation
 * New structure with brushes


 * Unnamed Abandoned Underground House
 * Can be found in the Deep Dark biome
 * Contains cobwebs and the unknown candle-like blocks
 * Stripped spruce log support beam runs across ceiling
 * Barrels, a double chest, and a blast furnace are included

Local Water Levels
 * A new generation aspect, which allow for certain areas of a world to generate with a water level different than another area
 * Allows for the generation of underground lakes, and oceans
 * Allows for the generation of many underground waterfalls


 * Mineral veins


 * Will be revamped, at least for copper

Gameplay

 * Archaeology
 * The player can find items and blocks in gravel and dirt by using the brush
 * Possible items:
 * Diamond block
 * Emerald block
 * Ceramic shards of varying color, which depict different images.


 * Dark Flashing
 * While in the deep dark biome, the screen occasionally darkens limiting the player's visibility. This may be the unknown candle like block's light darkening

Trivia

 * This update is the first update to add a new real-world metal into the game since Java Edition Classic 0.0.14a in 2009, and the first update to add a new ore to the overworld since Java Edition 12w21a for Java Edition 1.3.1 in mid 2012.

Minecraft Live 2020
Screenshots of the Caves and Cliffs Update from Minecraft Live 2020: