Vault of the Drow

The Vault of the Drow is an enormous cavern, containing the infamous city of the drow, Erelhei-Cinlu. A gleaming but sinister gem, the Vault is one of the most spectacular and awe-inspiring locations in the Underdark.

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Traveling to the great cavern is treacherous and extremely dangerous, a journey that only experienced adventurers should consider. Within its immense breadth lies a place of great beauty and mystery.

Deep beneath the Hellfurnace Mountains, the Vault of the Drow is a massive subterranean expanse, stretching over six miles long and nearly as wide. Its mineral-veined ceiling rises over 1000 fathoms, adorned with phosphorescent nodes that resemble an alien night sky. A decaying mass of tumkeoite glows like a plum-colored moon, casting an eerie luminescence over the cavern.

A singular road enters the Vault through a fissure in its southern wall, descending into a gorge illuminated by crushed, shimmering crystals. The Black Tower, an ancient stronghold, stands watch over this passage, serving as a checkpoint for travelers. Beyond it, the Vault opens into a landscape of fungal forests, crystalline formations, and vast stretches of lichen-covered rock.

Major bodies of water within the Vault include:

• The Pitchy Flow – A dark river flowing through the cavern.
• The Weeping Spring – A source that feeds into the Pitchy Flow.
• The Mere of Glooms – A hauntingly still expanse reflecting the Vault’s eerie sky.
• Lower Vault: Home to Erelhei-Cinlu, merchant villas, fungi forests, and warrior strongholds.
• Upper Vault: The seat of noble drow houses, including the infamous Fane of Lolth.

The principal drow city-state, Erelhei-Cinlu, is an ancient metropolis built after the wars between the light elves and dark elves. It lies on the southern bank of the Pitchy Flow, connected to the noble estates by the Flying Bridge.

• The Black Tower – The first checkpoint for non-drow travelers.
• Great Fane of Lolth – The foremost temple to the Demon Queen of Spiders, located beyond the noble plateau.
• The Ghetto of Foreigners – A district where non-drow are allowed, featuring temples to Nerull, Boccob, Vecna, and Tharizdun.
• The Ghetto of Chattels – A slave market district, heavily policed by Lolth’s priestesses.
• The Concourse – The central market and trade hub, home to Keptolo’s temple.
• Merchant Villas – Walled compounds housing the sixteen powerful merchant clans of the Lower Vault.
• Warrior Strongholds – Training grounds for male and female drow warrior societies.

Population and Society

Erelhei-Cinlu hosts a population of approximately 27,000 souls, consisting of:

• 40% drow
• 15% troglodytes
• 12% bugbears
• 10% surface dwellers and undead
• 4% mind flayers
• 4% trolls
• 4% yugoloths
• 3% kuo-toans
• 3% demons
• 1% svirfneblin
• 1% orcs
• 1% githyanki or githzerai

The city is a den of debauchery, decadence, and ruthless ambition. Its streets are lined with gambling dens, brothels, drug saloons, and torture parlors. Nobles ride nightmares through the crowded thoroughfares, while beggars and enslaved beings line the alleys. Male drow patrol the city, but their primary concern is preventing riots rather than enforcing law and order.

Religion

The dominant religion of Erelhei-Cinlu is the worship of Lolth, the Spider Queen, whose Great Fane is the most powerful temple in the city. Other deities venerated include:

• Keptolo, Lolth’s consort, worshiped at the Concourse.
• Kiaransali, whose priesthood dominates the Ghetto of Chattels.
• Zinzerena, a lesser but still influential goddess.
• Various foreign gods worshiped in the Ghetto of Foreigners, including Incabulos, Ralishaz, Vecna, and Tharizdun.

History and Politics

The noble house Eilservs once dominated Erelhei-Cinlu, seeking to establish a single ruling queen. When the other noble houses opposed them, they abandoned Lolth for the Elder Elemental God. This act led to their downfall when adventurers disrupted their schemes, leading to their exile and the destruction of their power base.

Culture and Economy

Drow society is matriarchal, with priestesses of Lolth holding the highest power. Male drow rarely attain authority unless they are powerful wizards. Trade thrives in magical weapons, poisons, slaves, and exotic Underdark goods.

Despite their wealth and power, drow culture is steeped in betrayal, assassination, and intrigue. Only the strong survive—or rather, those who survive are deemed strong.

Encounters and Perils

The streets of Erelhei-Cinlu are teeming with illithids, kuo-toans, demons, and undead. Non-drow are required to wear green silk cloaks marking them as outsiders. Those found without such cloaks are swiftly enslaved or executed.

Final Notes

The Vault of the Drow remains one of the most infamous and perilous locations in all of Oerth. For those who dare to tread its darkened streets, opportunities abound—but so do unimaginable horrors.