In this seed you will find a unique place: two rare biomes located on the same island. To find the mushroom biome inside mesa, go to coordinates -1000 ~ 1000. You can go to the island through the swamp where two witches live: one hut is located at coordinates 8 ~ 360, and the other – at 88 ~ 520.
How to use Mushroom Biome Inside Mesa seed
Start the Singleplayer mode
Select ‘Create New World’
Then click on ‘More World Options…’
In the ‘Seed for the World generation’ field, enter 15405247512687