Underdark

Not necessarily a single system of dungeons, Underdark refers to the vast, largely interconnected world that plunges deep into the depths of the earth. While their origins and history are as deep and many-faceted as the caverns themselves, they are universally thought of as something to be avoided. While many shallower parts of the Underdark have long since been separated from the larger systems and now act as castle dungeons, sewers and other uses civilizations on the surface can find for them, nonetheless any part of it can be dangerous, as the twisting stone guts of the world can often time shift or bend at a whim, and countless species of under-dwelling nature lurk and burrow from system to system, finding themselves among civilized folks unaware.

Most of what people know of the Underdark are tales of goblins and witches designed to scare naughty children into obedience, and only the bravest, most powerful or clearly suicidal men and women willingly descend to any great depth for any great length of time to capture what little part of what is surely a aeons-old history and unimaginable lost riches from ancient civilizations long sunk and lost into the earth itself.

Underdark

R&B MichaelBuhler