Alex's Caves — Guide

Getting Started

1. Install a mod loader that matches this build (NeoForge for the latest versions).
2. Install Citadel. Alex's Caves has a hard dependency on the Citadel library - drop a matching Citadel jar into your mods folder too, or the game will crash on load.
3. Place both jars (Alex's Caves + Citadel) into .minecraft/mods.
4. Launch and explore. The new cave biomes generate underground across the Overworld. Dig down and look for the tell-tale signs of each biome - magnetic metal, prehistoric fossils, glowing nuclear waste, or a bottomless flooded chasm.
5. Bring gear. Each biome has its own hazards (radiation, deep-sea pressure, aggressive bosses), so read the biome sections below before diving in.

Every creature also has a spawn egg in the Creative inventory if you want to study a mob before hunting for its home biome.

Magnetic Caves

A metallic cavern of galena ore, magnetized rails, and floating iron. Everything here reacts to magnetism.

Creatures: Magnetron (a towering magnetic golem), Ferrouslime (a metal slime), Boundroid, Teletor, Notor, and the Quarry Smasher.

What you get: magnetic ores and metals, the Galena Gauntlet and magnetic weapons that pull or push mobs and metal, plus decorative industrial blocks. Use magnetism to move metal blocks and traverse the cavern.

Primordial Caves

A lush prehistoric jungle-cave full of dinosaurs, fossils, and amber. The most iconic Alex's Caves biome.

Creatures: Tremorsaurus (a roaring tyrannosaur), Grottoceratops (a horned ceratopsian), Vallumraptor (a pack-hunting raptor), Subterranodon (a flying pterosaur), Relicheirus, and the massive sauropod Atlatitan. The biome boss is the Luxtructosaurus, and the world-ending Tremorzilla can be summoned as an endgame threat.

What you get: fossils and amber (which can preserve items and mobs), limestone building blocks, Dinosaur Nuggets (a food), and prehistoric spears (Limestone Spear, Extinction Spear).

Toxic Caves

A radioactive wasteland of nuclear waste, uranium, and glowing hazards. Radiation will hurt you without protection.

Creatures: the Nucleeper (a nuclear creeper whose explosion is catastrophic), Radgill, Brainiac, and the Gammaroach (radioactive roaches that appear in groups).

What you get: uranium and nuclear materials, the Nuclear Bomb and remote detonator, hazmat protection, and a range of glowing decorative blocks. Handle the Nucleeper with extreme care - defusing a Nuclear Bomb is its own achievement.

Abyssal Chasm

A bottomless flooded trench of bioluminescent life, sunken wrecks, and crushing dark water - home to an entire deep-sea civilization.

Creatures: the Deep One society (Deep One, Deep One Knight, Deep One Mage), the enormous Hullbreaker, Lanternfish, Sea Pig, Tripodfish, Gossamer Worm, Trilocaris, and the Mine Guardian.

What you get: a rideable Submarine, deep-sea weapons and tools, glowing abyssal blocks, and trade with the Deep Ones. Watch for depth charges and mine guardians while exploring the wrecks.

Forlorn Hollows & Candy Cavity

Forlorn Hollows - a dark, eldritch cave of dread. Creatures include the Watcher, the boss Forsaken, Vesper bats, Corrodent, Underzealot, and Gloomoth. It yields dark, cursed gear such as the Desolate Dagger and Dark Arrows.

Candy Cavity - a bright, sugary wonderland. Creatures include the Gummy Bear, Caniac (a candy-cane hound), Gumbeeper, Candicorn, Licowitch, Gum Worm, Caramel Cube, Sweetish Fish, and the Gingerbread Man. It yields candy blocks, sweet foods, and playful gear like the Candy Cane Hook and Sugar Staff.