Umbravall

Umbravall, also known as The Throne of the Depths, is the primary city of the Drow, as well as being the entirety of their nation. It rumored to be completely unassailable by outside forces; due to the shifting labyrinth of tunnels that is said to be completely impassable by non-drow.
Umbravall, and indeed all of Drow society, is led by the divine Empress Vyalia and a cabal of powerful Grand Clerics.
It is home to the prison Deephold; possibly the highest security prison within Teshol and home to several dangerous convicts dating from present day, all the way back to pre-scalewar. Many of whom escaped alongside the ancient red dragon Daggerspine.