Har’ol d’lil Tanth, or City of the Wyrm was dubbed that by Ilharess Laenre' shi of Qu'ellar Sel'Vae, this name embodies her vision of shaping this dead city to become a place for all of the dark to enjoy.

Though, Har’ol d’lil Tanth hasn't always been known as such, once it was known as Obsulen, City of Portals.

Obsulen was a trade hub in the multiverse for the underdark, the walls of this vast cavern used to shimmer with the constant opening and closing of portals to every plane imaginable. The fruits of the underdark traded greedily with the outlanders. Even though the city populace was dominantly of underdark decent, derro, durgar, drow, illithid, even surfneblin, Obsulen's architecture is a mash of styles, the visiting outlanders having had a huge influence.The city of Portals flourished this way for thousands of years, they survived countless plots of jealous merchant houses and vengeful patrons.

The most notable plot to destroy Obsulen, was the Worm. An elemental mage named Zorn was scorned and duped by a drowess merchant. His revenge took the form of a giant worm from the elemental plane of earth. He tricked the worm into a portal to the city and once trapped in the cavern it wreaked havoc leveling two thirds of he above ground structures. The great worm was only stopped by the city's mages, by banning together, mingling their magics, it was frozen in place. Exactly how, is lost to the lack of historians in Obsulen, but the proof looms over the city as a constant reminder of a single mans thirst for vengeance...