The Abyss

The most recent discovery of the modern era, and quite possibly the most important. An adventurer's paradise filled with strange magic items and contraptions with unknown origins and uses.
  However great the artifacts produced by the Abyss are, they come at a cost. The farther you descend, the more difficult it becomes to ascend. For the Curse of the Abyss surrounds you as soon as you step foot inside.
  1st Layer: The Edge of the Abyss. At a depth of 0-1350 meters, the first layer is the most shallow. Ascending in the first layer will cause dizziness and nausea.
  2nd Layer: The Forest of Temptation. At a depth of 1350-2600 meters, the second layer is the first truly dangerous layer of the Abyss. The environment suddenly becomes like a tropical rainforest. Deeper still into this rainforest lies the "Inverted Forest", where trees grow upside-down and the wind blows exceedingly hard. Ascending here causes heavy nausea, headache, and numbness of limbs.
  3rd Layer: The Great Fault. Depth of 2600-7000 meters. A 4km vertical cliff with a large cave network around the main shaft. Aerial predators are very common here, such as the Crimson Splitjaw. Strains of ascent include vertigo combined with visual and auditory hallucinations.
  4th Layer: The Goblets of Giants. Depth of 7000-12000 meters. A mysterious, humid jungle of massive vines weaving to form giant concave discs that capture water from the air. At 9000 meters marks the Garden of the Flowers of Resilience, filled with Eternal Fortunes, the trademark flower of the Abyss. Though the beasts that dwell here are very, highly dangerous. Ascension causes intense full-body pain, dizziness from pain and varying amounts of internal and external bleeding across the body.
  5th Layer: The Sea of Corpses. Depth 12000-13000 meters. The thinnest vertically, but widest horizontally. A large monster filled sea with some crystallized sections held up by thick mud. This is the last layer of the Abyss where it is possible to return from alive, and intact. Ascension causes complete sensory deprivation, confusion, and self-harming behavior.
  6th Layer: The Capital of the Unreturned. Depth 13000-15500 meters. Any adventure past this point is known as one's "last dive", as any who try to ascend either succumb to death, or is deformed beyond recognition. There is a rumor that at the bottom of this layer lies a Golden City, where the ruins of a majestic city remain. Ascension causes death or loss of humanity.
  7th Layer: The Final Maelstrom. Depth 15500-????? meters. It is almost completely unknown what lies here. Although ascension would cause certain death.
  Taken basically completely from the anime/manga "Made in Abyss" by Akihito Tsukushi. So if you want spoilers on whats gonna be here, go watch/read that.
Type
Abyss