Terralith — World Generation Overhaul Mod for Minecraft

Terralith — World Generation Overhaul Mod for Minecraft

Terralith overhauls world generation in Minecraft and adds nearly a hundred new biomes, built exclusively from vanilla blocks — without a single new item or block. The 1.18 generation update brought increased world height and expansive caves, but the variety of surface landscapes remained somewhat repetitive. The mod expands it with dozens of climate zones, new terrain types, and structures. Thanks to the absence of custom blocks, it can even be installed on vanilla servers as a datapack.

Biomes

The core of Terralith is biomes. Aside from nearly a hundred new zones, the mod updates almost every vanilla biome and introduces terrain types previously unseen in the game: canyons, shattered biomes, floating islands, and deep ocean trenches.

The realistic branch features Yellowstone, inspired by the real national park, Yosemite Cliffs with steep rock faces, the flat Highlands for massive builds, Volcanic Peaks, and desert oases. The fantasy branch shifts the palette towards unusual colors: the purple Moonlight Grove, the Amethyst Rainforest, and the red-rock Scarlet Mountains. Rare Mirage Isles and nostalgic Alpha Islands, reminiscent of early game versions, can occasionally be found in the ocean.

A fantasy biome with a mage tower in purple tones

A biome with red trees

Different biomes side by side

Underground Biomes

Caves have also been rewritten. The Underground Jungle is overgrown with tropical greenery beneath the surface; Fungal Caves are covered in mushrooms; Infested Caves hide silverfish in ore blocks. Stone caves generate separately — for granite, andesite, diorite, and tuff: they replace the usual scattered veins of these rocks underground.

Underground biomes

Structures

The biomes are complemented by over 20 structures, also built from vanilla blocks. The most prominent is the Spire: a tall tower piercing the sky in the coldest, icy zones. Fortified Villages occasionally appear in plains and deserts — settlements with defensive walls, dedicated profession buildings, and custom loot tables. Magical biomes feature Mage Towers holding treasures inside.

There are many smaller landmarks: the simple Glacial Hut for spending the night, the Igloo, small Rubble ruins in several variants for different biomes, the Desert Outpost inhabited by pillagers, and the early-game Valley Lodge. Caves hide their own structures as well. You can locate a specific object using the /locate structure command, for example, terralith:fortified_village.

A fortified village with a defensive wall in the center

Skylands and World Types

A separate generation module is Skylands: four "season" biomes that form as sky islands above deep oceans.

Mod version 2.6.0 added support for all world types: Terralith works with Superflat, Single Biome, Large Biomes, and Amplified. Two custom types are also added. terralith:amplified_large_biomes combines Amplified and Large Biomes in one world. terralith:all_skylands creates an empty world completely filled with Skylands islands.

Mod and Datapack

Terralith exists in two forms. The datapack version is installed on a world or server and doesn't require a client-side mod — perfect for vanilla servers. The mod version (Fabric, NeoForge, Forge, Quilt) offers more: a config file, new world types, and better integration with other biome generation mods.

Starting from 2.6.0, these two forms diverged: the internal structure of the mod version and the datapack differs, so transferring a world between them is not possible — it will corrupt generation. Choose one form when creating the world and stick with it.

Config

The mod version stores settings in the terralith.json file. Each module is toggled separately; editing is also available via mod menus — Mod Menu for Fabric or the built-in NeoForge menu.

Conclusion

Terralith makes world generation diverse without adding a single new block. Its main limitation is irreversibility: the mod cannot be removed from a world. It is suitable for builders who need large, flat Highlands for construction, explorers seeking 95+ biomes and structures, and server owners looking to refresh the landscape without forcing client-side mods on players.