Java Edition 21w06a

Not to be confused with 20w06a.

 Note: the 2 "flavors" are what the 2 new cave types, spaghetti and cheese caves, are called on Minecraft.net.

21w06a is the ninth snapshot for Java Edition 1.17, released on February 10, 2021, which adds new cave generation and a new build height limit.

Worlds created prior to this snapshot cannot be loaded in this version, due to there being no upgrade path towards the new height.

World generation

 * Caves
 * Added aquifers and new noise caves, which come in two "flavors," 'spaghetti' and 'cheese' caves.


 * Spaghetti caves


 * Long noodle-like caves, sometimes wide like tagliatelle.


 * Cheese caves
 * Like the holes in swiss cheese, often form caverns of various sizes.


 * The old cave generation still generates, combining with the new caves.


 * The new generation also form cave entrances when they intersect with land.


 * Aquifers
 * Used to generate bodies of water in new caves. As of now, it's only used below Y=31, meaning any noise caves between the two heights are flooded with water. This will be fixed later.


 * Magma blocks may generate at the bottom of these new water bodies, creating downward bubble columns.


 * Replaces the old underwater cave carvers/canyons.


 * Mineshaft
 * Mineshaft pieces no longer generate if they were fully floating in the air.


 * Corridors now generate with log pillars for support if needed.


 * There are no more floating cobwebs.

Blocks

 * Hanging Roots
 * The texture has been changed.


 * Small Dripleaf
 * The texture has been changed.

General

 * World
 * Raised the height limit to 384 blocks.
 * The height limit now goes from -64 up to 320 blocks.