Place
Zaran Mor
The drow capital, and the rock it is under
Zaran Mor was not one drow city among many. It concentrated their civilization in a single immense cavern: its matriarchs, archives, temples, fighting schools, and most advanced Psychic knowledge. Smaller colonies supplied it, while other Underdark peoples and powerful creatures served it. The drows had little interest in conquering the surface. Zaran Mor already possessed the darkness, food, temperature, and territory their long lives had taught them to prefer.
The city grew slowly. Few children were born, education lasted for decades, and ancient women controlled reproduction and political life. Their Psychic power, memories, descendants, and students made them living institutions. The drows revered those elders; worshipping an outside monster belonged to the broken society that followed them.
One of the powerful creatures held in Zaran Mor's service was an elemental. Perennus Albion fought it in the Underdark and the cavern came down on the city. He had gone below for something else entirely. He walked back out with a drow child and handed her to House Leblanc, where she grew up as their spy, still carrying half of a school of the sword nobody was left to finish teaching her (see Shara and Shara's Style).
The survivors scattered, increased their birth rate, shortened their education, and began gathering beneath Psychic monsters strong enough to protect several families at once. Qormuza took a colony outright, Marcus Crassus bought one, and Cauchemar acquired advisers and worshippers. See 15.
The rock came down a second time. Aldor fought the Aboleth Jerax in the cavern, under a summer sky he had conjured over it, and the ceiling collapsed on the fight. Sobiesansky survived that one as green vapour under the rubble.
Nobody has dug. The site is known, and the rock above it is ordinary rock. Beneath it remain the weapons, memories, bound servants, and Psychic knowledge of Zaran Mor. Digging is a project, and a project needs somebody who will still be in charge when it finishes.