When you first spawn on this seed, you’ll be on a tiny island with nothing but some grass and dandelions. If you’re willing to do the swimming (or boating if you can find a tree to make a boat with), this seed holds much greater things than that, though. You can find a mushroom island (a very rare biome) and a savanna plateau M biome not too far across the ocean.
Minecraft PC 1.11 Seed: -1057800294167584229
You’ll see several other small islands around the spawn island, but you need to head northeast to find the one we’re looking for. Along the way, you’ll pass an island with trees (this would be a good place to build a boat). Keep going until -163 / 63 / 140. This is the beginning of the mushroom island.
The Mushroom Island
This purple island is covered in giant mushrooms and is the only place that mooshrooms spawn naturally. (And this island has plenty of them!)
You can also find regular-sized mushrooms growing in bright sunlight, and other mobs don’t spawn naturally in this biome. Even if you’re in the cave underground, you won’t have to worry about running into monsters by natural spawning.
Usually, mushroom islands are isolated and separate from other biomes, but this one connects to a savanna biome.
The savanna biome, complete with acacia trees and brown grass, makes up the other half of this island, and if you keep walking east on the island, you’ll find another landmass that starts as a desert.
If you’re willing to do the traveling, you can keep traveling east through the desert to find a savanna plateau M biome.
This is one of the rarer variants of the savanna. It has tall, steep mountains that go above the clouds. Even at that high level, acacia trees can still grow on the mountain top. It gives a stark contrast to the usually flat or rounded hills of this biome.
This seed is all about the aesthetics and rare biomes, but keep exploring for yourself to see what else these interesting islands may hold.