New Guistenal
From Multiversal Omnipedia
New Guistenal is a secret, subterranean city in the Tablelands of Athas ruled by the undead sorcerer-king Dregoth.
After the destruction of Guistenal, Dregoth constructed a new city under the ruins of the old and populated entirely the a race of his own creation, the dray. During construction of the hidden city, he uncovered an artifact possibly unique in all of Athas: A portal allowing travel to other worlds.
Dregoth left Athas to explore the multiverse, leaving New Guistenal in the hands of the dray, leaving them with a prediction of a day of light, when he will return and the dray shall rule all of Athas. Dregoth has recently returned, and the preparations for the day of light are underway...