Minecraft Java Edition mod

Alex Caves Mod: six rare biomes under your Overworld

Alex's Caves adds magnetic caverns, a prehistoric jungle, radioactive tunnels, a deep-sea trench, a pitch-dark hollow and a cave made of candy. This site explains how to install it, how to find each biome and how to download it safely.

Download Alex Caves Mod Read the install guide
Illustrated cross-section of the Overworld showing six rare cave biome pockets connected by a dashed route from an underground cabin

Java 1.20.1official target

6 biomesall rare by design

Needs Citadelshared library

What is it?

What is Alex Caves Mod?

Alex's Caves is a large content mod for Minecraft Java Edition, created by Alexthe668 (AlexModGuy) with the artist Noonyeyz. It adds six cave biomes to the Overworld, each with its own blocks, items, creatures, lighting, fog and music.

The biomes are deliberately rare, about as uncommon as mushroom fields in vanilla Minecraft. Instead of hoping to stumble into one, you follow a trail: underground cabins, cave tablets, and maps that point the way.

People searching for "Alex Caves Mod" usually mean this project. The official name uses an apostrophe, Alex's Caves.

Open field guide with a cave tablet on one page and a cave biome map on the other
The mod's in-game guide book, the Cave Compendium, fills in as you research tablets.
  1. Metal
    Magnetic CavesAttraction, repulsion and machinery built on magnetism.
  2. Prehistoric
    Primordial CavesAn underground jungle with dinosaurs and caveman houses.
  3. Hazard
    Toxic CavesRadiation, acid and a glow you should keep your distance from.
  4. Deep sea
    Abyssal ChasmA dark ocean trench and the Deep Ones who live there.
  5. Darkness
    Forlorn HollowsNear-total darkness and the most hostile residents.
  6. Newest
    Candy CavityA cave of sweets, added in the 2.0 update line.

Want the details? Read the guide to all six biomes.

Features

What the mod adds

Each biome is built around one idea, and the items and creatures follow from it.

Six hand-built cave biomes

Every biome has its own terrain, blocks, ambient particles, fog, light colour and soundtrack, created by a dedicated art and sound team.

A discovery trail, not luck

Underground cabins hold cave tablets. Research them into codices and craft maps that search thousands of blocks for a specific biome.

Gear that matches each cave

Magnetic tools and machines, hazmat protection for radiation, diving gear for the deep, and gingerbread armour from the Candy Cavity.

New creatures and bosses

Dinosaurs you can tame or flee from, an underwater civilisation you can trade with, and bosses such as the Luxtructosaurus and Tremorzilla.

Plays well with key mods

The mod description lists built-in compatibility with Just Enough Items for recipes and with Alex's Mobs from the same developer.

How it works

From install to your first rare cave

Five steps, in the order the mod intends you to take them.

  1. Install Forge and Citadel

    Set up Forge for Minecraft Java 1.20.1 and add both the Alex's Caves and Citadel jars to your mods folder.

  2. Find an underground cabin

    These small structures sit below the surface in most Overworld biomes and hold a Spelunkery Table and a barrel of cave tablets.

  3. Research your tablets

    Use the Spelunkery Table to turn tablets into Cave Codices and unlock chapters of the Cave Compendium.

  4. Craft a cave biome map

    Combine a codex with eight paper, then use the map to scan roughly 10,000 blocks for its biome.

  5. Travel and explore

    Follow the map, pack for the biome's hazards, and dig down into a cave nobody else has mapped.

Use cases

Who it suits

Survival players who miss the feeling of discovery

Because the biomes are rare and tracked down with maps, finding one feels like an expedition rather than a detour. It rewards preparation and long journeys.

Modpack builders

A large content mod with its own progression, often used as an exploration pillar in Forge 1.20.1 packs.

Multiplayer servers

Shared expeditions work well, as long as the server and every player use matching files.

Builders looking for new materials

Each biome brings its own block palette, from metallic and prehistoric to sugary.

Players on Bedrock or phones

This mod isn't for you yet, and we'd rather say so. Here's why, and what exists instead.

Compatibility

What it runs on

Based on the developers' official release. Community ports are listed separately, because they are made by other people.

Alex's Caves platform and version support, checked September 2026
Setup Status Notes
Java 1.20.1 with Forge Official The release target. Needs the Citadel library.
Java 1.20.1 with NeoForge Listed Some official file listings also tag NeoForge 1.20.1. Check the file page.
Java 1.21.1 Ports only Unofficial community ports exist. See the 1.21.1 guide.
Fabric or Quilt No official build A third-party continuation claims Fabric builds. See the Fabric guide.
Bedrock, MCPE, consoles Not available Java mods can't run on Bedrock.
Shader packs Not recommended They can override each biome's fog and lighting.
Just Enough Items, Alex's Mobs Built in Compatibility listed in the mod description.
Guides

Start with these guides

Nine guides cover setup, versions, exploration and fixes.

See all nine guides
A folded map with a dashed route from an underground cabin to a map pin, with a compass
Exploration

How to find Alex's Caves biomes

Underground cabins, cave tablets, codices and maps: the full route from spawn to a rare biome.

 A mods folder holding the Alex's Caves and Citadel jar files next to an arrow pointing into Forge 1.20.1
Setup

How to install Alex Caves Mod on Forge 1.20.1

Forge, Citadel and the mods folder, in the order that avoids the usual first-launch errors.

 A log window with highlighted error lines beside a warning sign and a wrench
Troubleshooting

Alex Caves Mod not working? Fixes for common problems

Missing Citadel, wrong version, Java errors and memory crashes, diagnosed from the error you see.
Pros and cons

The honest trade-offs

What works well

  • Distinct biomesEach cave has its own look, sound, creatures and mechanics rather than a recoloured palette.
  • Built-in progressionCabins, tablets, codices and maps give exploration a clear path.
  • In-game documentationThe Cave Compendium explains each biome as you unlock it.
  • Open source codeThe repository is public, which is why community ports exist.

What to be aware of

  • One official versionThe developers' release targets Minecraft 1.20.1 on Forge.
  • Java Edition onlyNo official Bedrock, Pocket Edition or console release.
  • Heavier than small modsA large jar and rich effects mean memory settings matter.
  • Shaders clashMany shader packs override the biomes' custom lighting.
Installation

Setup checklist

The short version. The full installation guide covers launchers, servers and first-launch checks.

Using the source ZIP?

The archive in the download section is source code. To play, use a compiled release jar for your Minecraft version.

  1. Confirm Java Edition 1.20.1

    The official release doesn't load on other Minecraft versions or on Bedrock.

  2. Install Forge for 1.20.1

    Run the Forge installer once, or create a Forge instance in your launcher.

  3. Get Alex's Caves and Citadel

    Two .jar files, both for Forge 1.20.1, from the official project pages.

  4. Copy both into the mods folder

    Leave them zipped. Don't rename or extract them.

  5. Launch and check the Mods list

    Both should appear. Then create a new test world.

  6. Match files on servers

    The server and every player need the same versions.

Download

Download Alex Caves Mod

This button downloads a ZIP of the Alex's Caves project from the AlexModGuy/AlexsCaves repository on GitHub, taken from its main branch.

  • Minecraft Java 1.20.1
  • Forge
  • Requires Citadel
  • Source code ZIP
Download Alex Caves Mod

Before you open it: this archive is the project's source code, not a playable .jar. It won't load from your mods folder as it is. For playing, use a compiled release for your game version; our safe download guide explains where the official release files are published.

The main branch can differ from the latest published release. This site is not affiliated with the mod's developers.

Open crate with a download arrow and a crystal
Release information

Release facts at a glance

Taken from the mod's official project pages when we checked in September 2026.

Latest official release listed
2.0.2Uploaded to CurseForge on 26 October 2024
Minecraft version
Java 1.20.1
Mod loader
Forge
Required library
Citadel
Biomes
6Candy Cavity joined in the 2.0 line
Creators
Alexthe668 and Noonyeyz
Source repository
AlexModGuy/AlexsCaveson GitHub
What this site's button delivers
Source ZIP of the main branchNot a compiled release; contents follow the repository
Licence
Open sourceSee the licence file in the repository for the exact terms

Release details can change after our check. The official project pages are the authority on the current version.

Troubleshooting

Quick fixes for common problems

More detail, and more problems, in the crash and error guide.

The game says Citadel is missing

Add the Citadel jar for Forge 1.20.1 to the same mods folder. If it's already there, it's probably the wrong version.

The mod doesn't show up at all

Check that you launched the Forge 1.20.1 profile, not vanilla or Fabric, and that the file ends in .jar.

I put the downloaded ZIP in mods

That archive is source code. Remove it and use a compiled release jar instead.

Crash with OutOfMemoryError

Give the instance more memory. See the performance guide for sensible amounts.

Biomes look washed out or wrong

Turn off shader packs. They often replace the biomes' own fog and lighting.

Kicked from a server

Your mod and Citadel versions must match the server's exactly.

FAQ

Frequently asked questions

Twenty answers, split between getting the mod running and playing it.

Download and setup

Versions, loaders, libraries and platforms

Yes. The mod is distributed at no cost on its official project pages, and this guide site doesn't charge for anything either.

It downloads a ZIP of the main branch of the AlexModGuy/AlexsCaves GitHub repository. That's the mod's source code, useful for reading or building it. It is not a ready-to-play jar, so it won't load if you drop it into your mods folder.

The official release targets Minecraft Java Edition 1.20.1. The latest official file we found when checking in September 2026 was 2.0.2, uploaded in October 2024.

Yes. The official build is a Forge mod, so you need a Forge installation for Minecraft 1.20.1. Launchers such as CurseForge or Prism can set that up for you.

Citadel is a shared library used by the developer's mods. Alex's Caves will not start without it, so place the Citadel build for Forge 1.20.1 in the same mods folder.

Not from the mod's developers. Alex's Caves is a Java Edition mod, and Bedrock can't load Java mods. Some Bedrock add-ons borrow the theme or the name, but they are separate projects by other creators.

There's no official Fabric build. Independent community ports claim Fabric support, but they're unofficial and come with their own dependencies. For the mod as released, use Forge 1.20.1.

Only through community ports that describe themselves as unofficial. The developers' own release line is for 1.20.1.

Yes. The mod has an official Modrinth project page as well as a CurseForge page, and both list the release files with their game version and loader.

Yes, for multiplayer. Alex's Caves adds blocks, items and creatures, so the server and every player need matching versions of the mod and of Citadel.

Playing and exploring

Biomes, maps, bosses and settings

Six: the Magnetic Caves, Primordial Caves, Toxic Caves, Abyssal Chasm, Forlorn Hollows and Candy Cavity. All of them are rare on purpose.

Start by locating an underground cabin. Its barrel holds cave tablets, which you research into cave codices and then craft into cave biome maps that point to the biome.

Each tablet belongs to one biome, which is revealed once it is researched at the Spelunkery Table. The result, a Cave Codex, unlocks Compendium chapters and is the key ingredient for a cave map.

Craft one Cave Codex with eight paper. Hold the blank map and use it, and it scans a radius of about 10,000 blocks for its biome. The search can take a few minutes.

It's the mod's in-game guide book. Using codices unlocks four chapters per biome: general information, resources, inhabitants and utilities.

The biomes are rare by design. The map stays blank and can be reused, so travel a long way from where you tried and use it again.

The developers recommend playing without shaders, because many shader packs override the custom fog, lighting and colours each biome relies on.

Yes. The mod description lists built-in compatibility with Just Enough Items and Alex's Mobs.

Yes. Examples include the Luxtructosaurus in the Primordial Caves, the Tremorzilla linked to the Toxic Caves, and the Forsaken of the Forlorn Hollows.

You can, but new biomes and structures only generate in chunks created after the mod is installed, so you'll need to explore fresh terrain. Back up the world before you try.