Found a very large Mushroom Fields biome while playing Hardcore.
Seed: -1217667290973530583
Version: Java Edition 1.21.x
World type: Vanilla (no mods, no datapacks)
Approximate size (measured on Chunkbase):
~4100 blocks wide (X axis)
~700 blocks tall (Z axis)
Approximate center coordinates:
X ≈ -2000, Z ≈ 2100
It appears to be a single contiguous Mushroom Fields biome,
much larger than the usual mushroom islands.
Great for a safe Hardcore base (no hostile mob spawns).
Chunkbase map:
https://www.chunkbase.com/apps/seed-map#seed=-1217667290973530583&platform=java_1_21_9&dimension=overworld
by azoturko