Minecraft: Java Edition 21w06a snapshot on PC adds new cave generation from 'Caves and Cliffs Update'

Minecraft Caves and Cliffs Update Image
Minecraft Caves and Cliffs Update Image (Image credit: Mojang Studios)

What you need to know

  • Minecraft: Java Edition tests upcoming updates and changes through update "slices" known as snapshots.
  • The latest snapshot, 21w06a, finally adds the new-and-improved cave generation coming in the 'Caves and Cliffs Update.'
  • This means caves will be more varied, natural-looking, and all-around more beautiful and interesting.
  • Snapshot 21w06a also introduces aquifers, so it's possible to discover huge underwater lakes in Minecraft!

Minecraft has been testing and teasing the upcoming Caves and Cliffs Update ever since it was announced at Minecraft Live, but the Caves and Cliffs Update isn't expected until Summer 2021. Today, however, hardcore Minecrafters are getting a chance to test and play with one of the biggest changes coming in the Caves and Cliffs Update with all-new cave generation. Minecraft: Java Edition snapshot 21w06a is here with new "noise" caves and aquifers.

Noise caves refer to a new way to generate caves in Minecraft and should make for far more diverse and exciting caves wherever you go. The idea of this new system is also to make cave systems appear more natural as you explore them. Aquifers replace the aging underwater systems present in Minecraft to allow for "local water surface levels," meaning you can come across entire underwater lakes!

This is undoubtedly the biggest Caves and Cliffs Update snapshot we've seen yet, and it's exhilarating to see such a significant feature come to life after months of waiting. If you're unsure how to test out snapshots with Minecraft: Java Edition, check out our guide on playing with Minecraft: Java Edition snapshots.

Otherwise, you'll have to wait along with the rest of us for the massive Caves and Cliffs Update to come to everyone. The Caves and Cliffs Update includes much more than just new cave generation and is one of the most extensive updates Minecraft has seen yet. If you're as excited for it as I am, consider checking out our list of Best Minecraft Merch, Toys, and Gifts to pick up something for yourself or a fellow Minecrafter in your life.

Keep in mind that this is an early snapshot for the Caves and Cliffs Update, so there are bound to be plenty of bugs in this snapshot. Mojang Studios warns of two major caveats with this specific release:

  • You'll be unable to open old worlds in this snapshot as there is currently no upgrade path towards the new world height
  • All caves of the new type between y31 and y63 will be flooded with water

The full changelog for Minecraft: Java Edition snapshot 21w06a includes:

New features

  • Added noise caves and aquifers

Noise caves & aquifers

  • Noise caves are a new way of generating caves, providing more natural variety. They can get really huge sometimes!
  • Noise caves come in two flavors:
    • Cheese caves. Like the holes in swiss cheese. These often form caverns of various sizes
    • Spaghetti caves. Long squiggly tunnels, sometimes wide like tagliatelle
  • No, they aren't loud. The "noise" part of noise caves is a technical term and has nothing to do with sound
  • The old cave carvers and canyons still generate, combining with the noise caves to form interesting cave systems
  • As with carvers, when noise caves intersect the surface they form cave entrances
  • An aquifer is an area with local water level, independent of sea level. Aquifers are used during world generation to generate bodies of water inside noise caves. This sometimes results in large underground lakes!
  • For now, aquifers are only used below y31. This means all noise caves between y31 and sea level (y63) will be flooded with water, and noise cave entrances will essentially be lakes. This will be fixed later
  • Magma sometimes generates at the bottom of underground bodies of water
  • Underwater cave carvers and underwater canyons have been removed since aquifers are used to generate water in caves instead


  • Overworld build and generation limits have been expanded
  • Mineshafts adapted to larger caves
  • You can no longer crouch or jump to prevent a big dripleaf from tilting
  • A big dripleaf will now tilt rather than break when hit by a projectile
  • A redstone powered big dripleaf will not tilt (except when hit by a projectile)
  • The textures for hanging roots and small dripleaves have been updated

World generation

  • Generation range and build limits have been expanded by 64 blocks up and 64 blocks down, to a total range of 384 blocks
  • Underground features, structures, and caves generate all the way down to y -64

Mineshaft changes

  • Mineshaft pieces don't generate if they would be fully floating in the air
  • Mineshaft corridors are supported by log pillars when needed
  • No floating cobwebs

Bug fixes

  • Big dripleaf can be broken with arrows in spawn protection
  • Small dripleaf can destroy any block



Zachary Boddy
Staff Writer

Zachary Boddy (They / Them) is a Staff Writer for Windows Central, primarily focused on covering the latest news in tech and gaming, the best Xbox and PC games, and the most interesting Windows and Xbox hardware. They have been gaming and writing for most of their life starting with the original Xbox, and started out as a freelancer for Windows Central and its sister sites in 2019. Now a full-fledged Staff Writer, Zachary has expanded from only writing about all things Minecraft to covering practically everything on which Windows Central is an expert, especially when it comes to Microsoft. You can find Zachary on Twitter @BoddyZachary.