Calamity Mod Wiki

"The scent of broken promises, pain, and eventual death is heavy in the air..."

The Brimstone Crag is a biome added by the Calamity Mod which spawns upon world creation. It can be found at the left side of The Underworld. It is composed of several large masses of Brimstone Slag half-buried in the ash, with deposits of Charred Ore interspersed within it. Across the crag there are several house-like structures, each containing a locked Shadow Chest with various Underworld items inside. Buried underneath the crags are three of these structures, which are unique in that they contain loot that is normally only obtainable from enemy drops, including the Philosopher's Stone.

Contacting lava in the Brimstone Crag causes the player to be inflicted with the Searing Lava debuff.

The Brimstone Elemental boss can be summoned here by using a Charred Idol.

In Death Mode, Brimstone geysers will also occasionally erupt from the lava.


Brimstone Crag
CharactersUnique TreasuresUnique DropsMusic
Despair StoneDespair Stone
Calamity EyeCalamity Eye
Heat SpiritHeat Spirit
Soul SlurperSoul Slurper

In Hardmode:

Cultist AssassinCultist Assassin

After the Brimstone Elemental has been defeated:

Charred SlimeCharred Slime


Brimstone ElementalBrimstone Elemental
From Shadow Chests
(from left to right, respectively):
Flower of FireFlower of Fire
Hellwing BowHellwing Bow
Lava CharmLava Charm
Dark LanceDark Lance

From Shadow Chests underneath Brimstone Slag
(from left to right, respectively):

Magma StoneMagma Stone
Obsidian RoseObsidian Rose
Philosopher's StonePhilosopher's Stone
From Soul Slurper:
Slurper PoleSlurper Pole

From all Brimstone Crag enemies in Hardmode:

Essence of ChaosEssence of Chaos

From Calamity Eyes:


From Calamity Eyes in Hardmode:

Blighted LensBlighted Lens

From Charred Slimes:

Charred OreCharred Ore

From all Brimstone Crag enemies after defeating Providence:

From terrain:
Brimstone SlagBrimstone Slag
Charred OreCharred Ore
Brimstone Slag WallBrimstone Slag Wall
Shadow ChestShadow Chest
Ancient DoorAncient Door
Ancient TableAncient Table
Ancient ChairAncient Chair

From Fishing:

Brimstone CrateBrimstone Crate
Brimstone FishBrimstone Fish
Charred LasherCharred Lasher
Coastal DemonfishCoastal Demonfish
Crag BullheadCrag Bullhead
Dragoon DrizzlefishDragoon Drizzlefish

From Fishing during Hardmode:

Chaotic FishChaotic Fish

From Fishing post-Providence:

Music Box (Brimstone Crag)Music Box (Brimstone Crag)


A picture of the stronger red color of lava in the Brimstone Crag.

  • Chunks of Brimstone Slag generate in the lowermost Cavern layer above the main Brimstone Crag, extending the biome out of the Underworld to some degree.
  • Player-created Brimstone Crag biomes are possible by placing more than 50 Brimstone Slag and/or Charred Ore in an area.
  • The three chests buried in the center of the biome are only accessible with the Molten Pickaxe, Rod of Discord, Actuators, or the Onyx Excavator Key.
  • While in the biome, Lava gains a stronger red color.


  • It is risky to visit this biome in Pre-Hardmode, as the enemies in it are quite powerful and killing them will garner very few rewards apart from money and the Slurper Pole.
  • The Philosopher's Stone can be obtained as soon as Skeletron is defeated, due to the player's access to Actuators and the Shadow Key.
  • In Hardmode, it is a great place to farm for Essence of Chaos, as all of the biome's inhabitants can drop it.
  • If the Hardmode Underworld's environment proves too inconvenient or treacherous, the blocks from the Brimstone Crag can be moved elsewhere in the world to form an artificial biome that the player has more control over.


  • The Brimstone Crag's theme is The Step Below Hell, which was composed by the artist DM DOKURO.
    • The main musical motifs are the themes of Brimstone Elemental, due to being the biome's boss, and Calamitas, due to her connection to the biome in the lore. A section of Supreme Calamitas' theme notably uses the melody from The Step Below Hell.
    • If the Calamity Music add-on mod is disabled, Eerie will play instead.
  • It was previously known as the "Profaned Crags". This was changed to prevent any kind of unwanted connections with Providence, the Profaned Goddess. Before that, it was known as the "Calamity biome".
  • In an earlier version of the mod, the Brimstone Crag was located on the far left edge of the Underworld, and featured several tall spires and a large eye-like formation underneath. This was changed due to taking a significant amount of time to generate.


Smoking slag, crackling flames, and charred stone are all that remain of the underworld’s once-grand civilization. Centuries ago, primitive societies found their way to these scorching caverns and discovered power in the form of an eternal red flame. They grew to worship the flame and its otherworldly might - and over the course of generations, founded a mighty empire of magic as they learned to harness the red flame for themselves.

Their hierarchy of privilege and magical prowess fostered great conflict. Those in power hoarded power, restricting the lower classes’ knowledge and suppressing research that threatened them. One clan revolted against the restrictive and greedy ways of the capitol - but like many others in the empire’s history, they were exiled. The capitol waited for them to return for revenge, when those in power would crush them as an example. However, that day would never come. For those exiled, had come upon a curious revelation. Centuries spent living in the presence of the eternal flame, had led to these mages to develop a natural connection to the brand of magic which utilized brimstone, rather than a forced link, such as the rituals carried out by by the capitol. Forced to stop relying on the eternal flame, they began to develop their own style of magic, drawing from darker forces. As they built upon their own strength and training, this clan soon grew to be as powerful as those who controlled the eternal flame. Yet, they had long decided against revenge, realizing that such an act would lower them to the level of those in hell. Decades passed, and generations passed down the gift of brimstone magic, from parent to child. In time, it would be this clan to sire the Witch, Calamitas.

The empire of hell grew weak over the course of those long years, splintered by infighting and draconian rule. It was the beginning of a once-grand nation’s collapse - but its final death was at the hands of a conflict long past. An older Calamitas descended to the lands her ancestors called home and initiated a ruthless massacre, butchering the poor and weak on the outskirts first and then working in. Every death was another hateful soul twisted to her cause - every corpse, another revenant at her command - every life taken, another worshipper deprived from the eternal flame at the empire’s heart. These souls were twisted into abominations which to this day, haunt the slag. When no others remained, she corroded the essence of the flame with corrupt magic and flayed its spirit to the bone. Without joy, Calamitas fulfilled her orders and unknowingly avenged an ancient grudge long since lost to history. All that remained of that once-grand civilization was smoking slag, crackling flames, and charred stone.