The Vault

Beneath the Underground Jungle is the Vault, a large technical installation reminiscent of the Hiisi Base but far more dangerous.

Layout and hazards
The Vault resembles a giant abandoned underground factory, with rusted steel beams and platforms as far as the eye can see. Various machines resembling generators are dotted throughout the area which explode into an area of freezing vapour or fire upon destruction, depending on the gas emanating from their spout. Beneath the rusted metals you'll find compositions of Vault Rock, a hardier version of normal rock that is tough to dig through. Pools and vats of toxic sludge are common, with no naturally occurring water to purify it with. Explosive crates, propane tanks, toxic sludge barrels and oil barrels make a return. Large acid containers, both on the ground and hanging from the ceiling, make an appearance here. Occasionally, the path will be blocked by small pipes, but these can be dug through fairly easily.

Points of Interest

 * A giant vat of acid can often be found here. It is encased in glass, hinting that glass is the only material that doesn't corrode from exposure to acid. It can be easily broken just like ice, and if this is done then the contents will leak out, destroying much terrain (and possibly some enemies).
 * One of the Fungal Altars can be found here around the center of the biome, right before the entrance to the next Holy Mountain.
 * A large brain looking object can spawn here, destroying it will often reveal either a Max Health Upgrade or Treasure Chest inside.

Enemies
The Vault is littered with dangerous enemies, with a strong emphasis on robotic types and monstrosities: ... and more
 * Acid Sleazebag
 * Small Tentacler
 * Tentacler
 * Blob
 * Angry Blob
 * Rotting Corpse
 * Peerer
 * Maggot
 * Robo-Cop
 * Flamer
 * Cooler
 * Assassin Robot
 * Cricket
 * Drone
 * Tank
 * Rocket Tank
 * Turret

Some rarer spawns include:
 * Repair Drone
 * Lance Sentry
 * Laser Tank

Connected Areas
Proceeding through the portals at the bottom will lead you to the final area of the main path.

The Fungal Caverns can be accessed through the top-west corner of the biome, leading further west to an orb room as well as back up to the Underground Jungle.

Puzzles
A spherical structure found in the Vault. It has two randomly chosen symbols which determine what you must fill it with in order to receive one of two possible Unique wands, Varpuluuta or Arpaluu.

Only one of the clues needs to be followed for each puzzle.

The symbols and what you have to fill it with are: Symbols with multiple liquids listed means that you can use either one. In the case of the heart, you can use Lively Concoction or Pheromone, but they both must be accompanied by Healthium.