Depths (Disambiguation)

The Depths is a subregion of the Subterranean region that is important to the plot, accessed through a pipe at the bottom of the Filtration System, making it by far the lowest point in the game. There is no threat of Rain, and there are no natural predators. The only threat are the guardians of the area which will only bother the slugcat if the player has not unlocked the maximum Karma level. The only exit from the Depths is downwards, as there is no conventional way to climb back up the entrance shaft.

The Depths (Spoilers ahead)
The Depths is a series of seemingly abandoned temples and shrines. In order to progress through as intended, the player must have unlocked the 10th Karma level, typically acquired by visiting Five Pebbles or visiting four Echoes. Tall Guardians will quickly kill Slugcat if attempting to pass the west of the compound without a karma level of 10. A small room near the entrance of the depths raises Slugcat's Karma to its current max karma level as it passes. Attempting to make one's way past the guardians without a maximum karma of 10 will result in first in Slugcat being thrown back to the start of the room, and then being thrown against the ground, resulting in death. The Guardians have extremely high health pools and so cannot practically be killed.

As the player progresses downwards, the compound gives way to a loose cave system, and the slugcat will eventually reach a lake of golden dark liquid, known as the Void Sea. The slugcat cannot drown in this liquid, and swimming down into it will begin the ending sequence.

Trivia

 * There are multiple unintended ways to bypass the Guardians. With good timing it is possible to blind them with a flashbang fruit just long enough to sneak past. This is not possible as Hunter.
 * The guardians can also be bypassed by repeatedly swallowing and regurgitating a live Hazer, which causes them to target the Hazer instead.
 * It is also possible to fully despawn the Guardians by interrupting their room loading time. This is considered the simplest and fastest method of Guardian despawn and is used for any% speedruns.