Cavern

The Cavern is a fifth level biome. It is located beyond the Graveyard and served as a crystal mine for the King. It contains a variety of unique enemies in a series of carved tunnels, with a greenish visual atmosphere. The layout of the Cavern is particular, as it contains narrow shafts, probably used by the miners to move around the area, as well as floating platforms and pools of lava. The Cavern is initially the only way to reach the Giant, who is located in the Guardian's Haven.

Accessing the Cavern
To access it, the player needs to have downloaded the Rise of the Giant free DLC and to have beaten the Hand of the King at least once. Then, the player needs to bring the Cavern Key, which can be found behind a large hole in Prisoners' Quarters, to a portal found in the underground section of the Graveyard. Upon unlocking this portal, the passage to the Cavern will remain open forever.

An additional path to the Cavern exists in the Slumbering Sanctuary, but it requires the player to have beaten the Giant at least once and to have 2 BSC active.

General information

 * The Cavern contains 6 scrolls, including 4 Power Scrolls and 2 dual-stat scrolls. When 3 Boss Stem Cells are active, this biome has 4 guaranteed Scroll Fragments, and when 4/5 Boss Stem Cells are active, this biome has 5 guaranteed Scroll Fragments.
 * A food shop can be found regardless of difficulty

In the table below, you will find the gear level and enemy tier of the Cavern based on difficulty.

Boss Stem Cells rewards

 * 1 BSC: Treasure Chest
 * 2 BSC: Treasure Chest
 * 3 BSC: 2-choice item altar
 * 4 BSC: Treasure Chest; Festive Outfit

Exclusive blueprints
On the base level of difficulty, the Cavern is the only biome where the player can acquire the blueprints for the The Boy's Axe, Shrapnel Axes and Flawless weapons (see Enemies section).

In addition to those, a secret area at the end of the level contains the blueprint for the War Javelin, after a series of traps. In order to reach it, the player needs to possess the Spider and Homunculus Runes.

Finally, the Festive Outfit can be found by unlocking a door with the Garland Key. While the Garland Key can be found on any difficulty, in a secret area in the ceiling, the door itself can only be accessed on Nightmare/Hell mode, as it is located behind a 4 BSC door.

Enemies
The Cavern is home to a few unique enemies, including Ground Shakers, Demons and Slammers, in addition to more common ones. On higher difficulties, Lacerators are replaced by Failed Experiments.

In the table below, you will find which enemies are present in the Cavern depending on difficulty level. For each enemy, any common, uncommon, rare or legendary blueprints they carry are indicated. When applicable, the minimum difficulty level for blueprint acquisition is specified in brackets.

Alchemist Grimoires
A research grimoire can be found next to barrels of crystals and a vat containing a body. The Alchemist was apparently trying to use the crystals as the ingredient for a cure for the Malaise.


 * "We can do more with those crystals than sell them, I'm sure of that... Using them on corpses doesn't do anything for now, but I have to keep going!"

King Statues
A statue of the King can be found in the Cavern, next to barrels of crystals. The Beheaded notes how inflated the King's ego appears, that he would go so far as to bring statues all the way to the Cavern.


 * "Seriously? The King left one of his statues here? Is there no end to his ego?"

Other lore rooms
A lore room full of crystal barrels under the King's banner contains a letter left by a miner. It illustrates how isolated the miners were from the rest of the island's population, and how little they knew about the raging epidemic or the King's terrible measures to stop the spread of the Malaise. Despite being uninformed about the events outside of the Cavern, the miners were hiding weapons, which indicates they had met some monsters in their daily work routine and that the infection was reaching them.


 * "There are two kinds of people in the world: those with loaded crossbows and those that dig. ...We dig. We've dug for 7 months. 7 months here and still no news of the outside. I hope everything is fine."

A storage room full of crystals and banners of the King contains a letter left by a watchman, which alludes to the Giant. The letter states that the Giant, who previously guarded the Castle gates, has been slain due to an unknown feud between the King and him.


 * "The giant who was watching the castle gates is no more. What happened between him and the King, I wonder? ...I don't know what the Giant did, but judging by the spear, they must've had quite the... difference of opinion."

Loading screen quotes

 * "The Cave is a strange place where ice and fire coexist. The Alchemist never found out how."
 * "Mining was the most thankless job on the island. Many died buried under rubble, suffocated by toxic vapor, or killed by strange creatures..."
 * "Precious crystals were unearthed from this cave on the King's orders. Nobody knows what they were used for."
 * "Longest time without incident: 45 seconds."