Stormreach’s ruins reach miles into the earth. Sewer tunnels filled with vermin, discarded murder victims risen from the dead, prowling carrion crawlers, and moaning cloakers crisscross below the city’s streets. These dark mazes are home to thri-kreen tribes, kobold clans, and other creatures of darkness that do not suffer trespass lightly.
Any of these sewers might suddenly open into a yawning lost city, a shattered remnant of a bygone civilization of giants, drow, or any other of the races that called the ruins home ages ago. Traps and treasures dot these ruins, and monstrosities replace the original inhabitants. Only vestiges of these ancient civilizations survived whatever cataclysm claimed them. The twisted mockeries of their former inhabitants gibber and cavort in the lightless reaches of their people’s ruins, worshiping broken idols and gods who long ago turned their backs on them.
Necropolises teeming with the dead riddle the subterranean levels as well. Their decaying residents are restless, ever on the lookout for trespassers to feed their eternal hunger. Other more sinister powers use interlopers as pawns in some foul scheme to retake the city’s surface.
Finally, there remain potent magical prisons dating back to the age of the titan kings, buried below the buzzing streets of the city. Any number of terrors could be bound in these depths: a vampire lord of the Qabalrin elves, a titan king who sought to ascend to godhood, or a giant wizard trapped with the fiends he summoned to do his bidding. These horrors and more await brave heroes in the dark below the city.