
Underground Worlds
Adds underground biomes and underground dungeons, as well as some above ground structures, in a modular and configurable way.
Screenshots






About this Mod

Underground Worlds is a Minecraft mod that adds underground biomes and underground dungeons, as well as some above ground structures, in a modular and configurable way.
About
Underground Worlds was born as Underground Jungle, a mod that added an underground jungle biome and a jungle temple somewhat inspired by the one in Terraria.
When the development continued and more biomes were added, I decided it would have been better to put all biomes in the same mod and allow users to enable and disable features through config files instead of making a separate mod for each biome.
All biomes added by Underground Worlds can be enabled or disabled in the config.
The config can also disable certain features for each biome.
Features
Underground Worlds adds new underground biomes and structures, each with their own set of features.
Biomes and structures can have their exclusive mobs, set of tools, and other special items.

A full list of features can be found in the Wiki.
Additional information
When using Underground Worlds alongside other world generation mods, it may be necessary to use TerraBlender or Lithostitched for the biomes to generate in the world.
Main mod page
Modrinth: https://modrinth.com/mod/underground-worlds
Curseforge: https://www.curseforge.com/minecraft/mc-mods/underground-worlds
If you find this mod on other distribution platforms, these are NOT managed by me.
Credits
Mod Author: HexagonNico
Chiseled Temple Bricks texture by Matriax (CC-0)
Jungle bee model by FrostYieBoiy (CC-BY 4.0)
Wrapped model by Nightfoxy3D (CC-BY 4.0)
"Abbeyence" music by Spring (CC-BY 3.0)
Questions and answers
Q: Can I use this in my modpack?
A: Yes. You don't need to ask for permission. See License for details.
Q: Can you port this mod to 1.\d\d.\d?
A: I can, but remember that I'm a human being and porting the mod to another version requires additional effort to maintain each version. Please refrain from opening issues like "Port to 1.3.2 when".
Q: Can you translate this mod to ww_ww?
A: You can submit a pull request if you want to contribute!
License
This mod is licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International.
You are free to share, copy and redistribute this mod in any medium or format, including modpacks, adventure maps, and
other creations made within Minecraft, as long as you respect the following conditions.
- You must give appropriate credit.
- You may not use the mod for commercial purposes.
- If you create a modified version of this mod, you may not redistribute the modified version.
You are free to use this mod in any modpack, as long as you do not sell it via any means.
You cannot re-upload this mod on other mod distribution platforms.
Available Versions
How to Install Underground Worlds on Your Server
Order Server
Order a Minecraft Java server with at least 4 GB RAM (6 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (26.1.2).
Install Mod
Open the mod browser in the dashboard and search for "Underground Worlds". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
26.1.2, 26.1.1, 26.1 (+9 more)
Server-side
✓ RequiredRecommended RAM
6 GB(min. 4 GB)Frequently Asked Questions
Underground Worlds server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 4 GB RAM is allocated and the loader matches the mod version (26.1.2). You can switch loaders with one click in the panel.
Is Underground Worlds compatible with fabric and forge and neoforge?
Underground Worlds officially supports fabric, forge, neoforge for Minecraft 26.1.2, 26.1.1, 26.1. Note: Forge and Fabric mods are NOT cross-compatible – pick one loader and stick with it. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Underground Worlds – how to optimize performance?
Recommended RAM: 6 GB (per 5 players). Use /spark profiler to check if Underground Worlds consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
Similar Mods
Rent Modded Server
Install Underground Worlds with just one click on your server.
Details
- License
- Creative Commons Attribution Non Commercial No Derivatives 4.0 International
- Server-side
- Required