Notable Location - Underdark

A location that is known locally or further afield, as a landmark, place of history, magical danger or otherwise noteworthy.
The realms below are a place of twisting tunnels, constant darkness and strange magic. Encounters might occur in a forest of fungi, amid giant stalactites or by the side of a gaping chasm. It is a place of elemental earth and gates to far realms. Home to fungi creatures, the sightless peoples and monstrosities long forgotten.

tools for - fantasy location underdark

terrain:

The RoseGlade is a mushroom ring. It is at a crossroads. It is associated with nature magic. It is associated with undead.
Ruins of Karorchard is a ruins. It is at the edge of a lake. It is associated with insects. It is associated with death magic.
A druidic quarry.
A pretty ruins.
Magic courses through these crystal caves. Spells cast resonate loudly and attract psionic entities. The Astral plane overlaps here.
Market Canyon. Staircases and many chambers are cut into this wide canyon. Merchants often trade here the protection of a beholder.
The City of Curses is a canyon. It has a portal to the Draconic Garden of Death. It is associated with a powerful priest.
Serpentcrown Shrine is a colorful Manor. It has a splendid view. was the site of a notable battle - trolls fought mercenaries and a ruler's tomb is build here.
A foreboding Hold. It is known to a character, who has had visions of their death here. It is touched by arcane magic. was the site of a renowned battle - orcs fought a confederation of clans and ghosts haunt the place.
Several fetid pools contain various slimes and bubbling liquids. A highly intelligent roper hides among several large stalagmites.