Alex's Caves is a large-scale adventure mod that adds six entirely new underground cave biomes to the Minecraft Overworld, each packed with unique blocks, mobs, items, and mechanics, available for Minecraft Forge and NeoForge on version 1.20.1.
Vanilla Minecraft caves received a massive overhaul in the Caves & Cliffs update, but once you've seen every dripstone cluster and lush cave, the underground starts to feel predictable again. Alex's Caves solves that problem by hiding six extremely rare biomes beneath the surface — each one designed with its own atmosphere, fog, lighting, particles, and soundscape. With over 6.7 million downloads on Modrinth alone, it has become one of the most popular cave expansion mods in the community. Created by AlexModGuy (programmer) and Noonyeyz (artist), the mod reflects a level of visual and mechanical polish that rivals standalone indie games. It also requires the Citadel library mod to function, so make sure you grab that as well.
Key Features of Alex's Caves
- Six Unique Cave Biomes — The mod introduces the Magnetic Caves, Primordial Caves, Toxic Caves, Abyssal Chasm, Forlorn Hollows, and Candy Cavity. Each biome feels like stepping into a completely different world beneath the surface, giving veteran players dozens of hours of fresh exploration. The rarity of these biomes makes discovering one feel genuinely rewarding.
- Custom Mobs and Creatures — Every cave biome is populated with its own set of unique mobs that fit the environment thematically. Whether you're dodging prehistoric creatures in the Primordial Caves or encountering bizarre candy-themed life in the Candy Cavity, combat and exploration stay unpredictable. These aren't just reskinned zombies — each mob has distinct AI and attack patterns.
- Cave Compendium Guide Book — Finding the biomes isn't as simple as digging down. You first need to locate an Underground Cabin in the Overworld, where you'll find cave tablets and a Cave Compendium. This in-game guide book walks you through locating and surviving each biome, which adds a satisfying layer of discovery-based progression.
- Immersive Atmosphere and Ambience — Each biome features custom ambient particles, fog effects, brightness adjustments, and light coloring created by a dedicated sound team. The mod is best experienced without shaders, as many shader packs can interfere with the carefully tuned visual effects. This attention to atmosphere is what sets Alex's Caves apart from simpler biome mods.
- Unique Blocks, Items, and Equipment — The mod adds a wide variety of new blocks for building and decoration, along with weapons, tools, food, and magical items tied to each biome. Players who enjoy collecting gear and experimenting with new mechanics will find plenty of content to chase across all six biomes.
- Built-in Mod Compatibility — Alex's Caves ships with native support for Just Enough Items (JEI) and Alex's Mobs. If you're already running Alex's Mobs, the two mods complement each other naturally, expanding both surface and underground content from the same creative team.
- Transportation and Technology Mechanics — Several biomes introduce their own transportation methods and technology-themed mechanics, giving players new ways to move through the underground. These aren't gimmicks — they're integrated into the biome design and often essential for navigating the more dangerous areas.
Screenshots
How to Install Alex's Caves
- Download and install Minecraft Forge or NeoForge for Minecraft 1.20.1. Either loader works — choose whichever you already use.
- Download the Citadel library mod, which is a required dependency for Alex's Caves to load properly.
- Download the Alex's Caves mod file from the official source (link below).
- Place both the Citadel and Alex's Caves
.jarfiles into your.minecraft/modsfolder. On Windows, pressWin + R, type%appdata%.minecraftmods, and hit Enter. - Launch Minecraft using your Forge or NeoForge profile. Once in-game, start a new world and search for an Underground Cabin to begin your adventure.
Requirements & Compatibility
| Requirement | Details |
|---|---|
| Minecraft Version | 1.20.1 |
| Mod Loader | Minecraft Forge or NeoForge |
| Required Dependency | Citadel |
| Compatible With | Just Enough Items (JEI), Alex's Mobs |
| Shader Note | Best played without shaders — custom biome visuals may be altered |
| License | LGPL-3.0-only (open source) |
What's New
- Fixed double frostmint slabs incorrectly dropping only one item instead of two.
- Resolved multiple mob behavior bugs, including gum worms clipping underground when ridden on the surface and gummy bears instantly waking up on relog.
- Fixed depth charges not breaking blocks correctly and sugar rush interfering with nucleeper and nuclear bomb explosions.
- Corrected block model issues for west-facing gingerbarrels and gobthumper breaking when there is no block beneath it.
- Updated Spanish, Russian, Japanese, Traditional Chinese, and Simplified Chinese translations.
Pros and Cons
Pros
- Six distinct, handcrafted cave biomes with exceptional visual and audio design
- Built-in guide book system that makes discovery feel organic rather than random
- Massive amount of content — new mobs, blocks, items, food, equipment, and mechanics
- Active development with frequent bug fixes and translation updates
- Open source with native JEI and Alex's Mobs compatibility
Cons
- Currently limited to Minecraft 1.20.1 — no support for newer versions yet
- Requires the Citadel library as an additional dependency
- Shaders may interfere with the custom biome atmosphere and lighting
- Cave biomes are intentionally rare, which means longer search times before finding them
Alternatives to Alex's Caves
- YUNG's Better Caves — Overhauls vanilla cave generation with more varied shapes and sizes, ideal if you want improved caves without adding entirely new biomes.
- Alex's Mobs — From the same developer, this mod adds dozens of realistic and fantasy creatures to the Overworld surface, making it the perfect companion to Alex's Caves.
- The Bumblezone — Adds a bee-themed dimension accessed through bee nests, offering a similarly unique underground-style exploration experience with custom mechanics and mobs.
Download Alex's Caves
| Minecraft Version | Forge | NeoForge |
|---|---|---|
| For Minecraft 1.20.1 | Download | Download |
Always download mods from official sources to stay safe.
Frequently Asked Questions
Is Alex's Caves compatible with Fabric?
No — Alex's Caves is built exclusively for Minecraft Forge and NeoForge. There is no official Fabric port available, so you will need one of these two loaders installed to use the mod.
Do I need any other mods to run Alex's Caves?
Yes — you need the Citadel library mod installed alongside Alex's Caves. Without Citadel, the mod will not load. Optionally, installing Just Enough Items and Alex's Mobs will enhance the experience with recipe browsing and additional surface creatures.
Can I use shaders with Alex's Caves?
You can, but it is not recommended. The mod features custom ambient particles, fog effects, and lighting for each biome that many shader packs will override or distort. For the best visual experience, the developers suggest playing without shaders enabled.
How do I find the cave biomes in-game?
You need to find an Underground Cabin first. These cabins spawn naturally in the Overworld and contain loot barrels with cave tablets and a Cave Compendium book. The Compendium guides you to each of the six biomes — there is no way to stumble into them without this progression step.
Does Alex's Caves work on multiplayer servers?
Yes — the mod works on both singleplayer and multiplayer. All players on the server need to have the mod and Citadel installed on their client, and the server must also have both mods in its mods folder for everything to function correctly.
![[Let's Do] Meadow Mod (1.21.1) - thumbnail](http://mcinside.com/wp-content/uploads/2026/04/thumbnail-64-52x52.webp)
![Not Enough Recipe Book [NERB] Mod (1.21.11) - thumbnail](http://mcinside.com/wp-content/uploads/2026/04/thumbnail-63-52x52.webp)
