The Sunless Sea is a subterranean body of water northeast of the Vault of the Drow, in the Underdark. The White Kingdom lies to its north, and there is a kuo-toa shrine on the south shore, and there is a kuo-toa island-city in the center of the sea. The river Svartjet flows into the Sunless Sea, forming a delta; the drow have an outpost there. The ghouls have an outpost on the north shore commanded by Marquis Zun, Lord of Ice.
The black waters of the Sunless Sea are untroubled by tides or storms, although a mild wind blows across the surface. "Reefs" made from stalagmites or rubble from cave-ins make navigation somewhat hazardous.
- Gygax, Gary, David C. Sutherland III, David Cook, and Jeff Grubb. Queen of the Spiders. Lake Geneva, WI: TSR, 1986.
- Sargent, Carl. Night Below: An Underdark Campaign. Lake Geneva, WI: TSR, 1995.