Location from Icewind Dale by R.A. Salvatore / Wizards of the Coast / Black Isle Studios
A vast subterranean realm of lightless caverns, fungal forests, and alien civilizations — stretching beneath all of Faerûn in a nightmare mirror of the surface world.
The Underdark assaults every sense simultaneously. The air is thick, warm, and humid in the fungal caverns — tasting of spores and mineral-rich water — then abruptly cold and bone-dry in the connecting tunnels. Sound carries unpredictably: whispers travel miles through certain corridors while screams are swallowed whole in the great vaults. The constant dripping of water provides a metronomic background to everything. The darkness is not merely an absence of light but a presence — oppressive, disorienting, and alive with sounds that defy identification. Creatures adapted to this environment are uniformly dangerous: drow patrols, mind flayers, beholders, hook horrors, and things that have no name in surface languages. Navigation without magic is essentially impossible; tunnels branch fractally, loop back on themselves, and change as geological processes reshape them. The great drow city of Menzoberranzan occupies a cavern so vast it has its own weather patterns.
Immense caverns open without warning from narrow tunnels, their ceilings lost in darkness hundreds of feet above. Bioluminescent fungi and lichens provide the only natural light — a cold, blue-green glow that renders everything in alien hues. Stalactites and stalagmites of enormous size create forests of stone. Underground rivers and lakes of perfectly still, black water reflect the fungal light like dark mirrors. The architecture of the drow cities is deliberately intimidating — spires of black stone carved with spider motifs, illuminated by floating globes of faerie fire in violet and crimson.
Also known as: The Realms Below, The Night Below, The Underdark Beneath the North