D&D Notable Location - Underdark

A location that is known locally or further afield, as a landmark, place of history, magical danger or otherwise noteworthy.
The Underdark is 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 dark elves and aberrations from the Far Realms.

tools for - dnd5e location quest underdark

terrain:

The Forbidden Stairs. A long crystal stairway marked with statues of different underdark races. It is in the area of a forbiddance spell.
Goat Aerie is a mine. It is in a meadow. It is often home to spiders. is where a fiend was bound.
Ruins of Longgard is a shimmering gorge. It is protected by an awakened bat. is where famous lovers fled.
A sinister area of carved rooms. It is in a field. It is sacred to a power of death.
An enchanted chasm. It is the birthplace of a scheming adventurer. is said in tales that the Pillars of the Lunar Lord is nearby..
The City of Great Mists is an Asylum. It is in a field. It has a programmed illusion. It has a programmed illusion. was a place of executions.
The numerous beetles here live in symbiosis with several tall purple mushrooms. They are unaffected by the drifting poisonous spores.
Several fetid pools contain various slimes and bubbling liquids. A highly intelligent roper hides among several large stalagmites.
A sentient ruins. It is at a crossroads. It is associated with death magic. is said that the Resonant Arena of the Dead is nearby..
A floating canyon. It is at a river crossing. It has a splendid view.