Niikazad

 was a dungeon which began as a mine and dwelling of dwemer. In the centuries after the dwemer disappeared, it became the home of powerful wizards, criminal groups, and convicted felons.

History
Millenia before the first era the ancestors of the nemer first started to dig crypts in this area. The ancient dungeon itself started as a mine and dwelling of dwemer that formed an alliance with the Nemer. In the centuries after the dwemer vanished, it became the home of powerful wizards, criminal groups, and convicted felons.

The most famous of those to control the halls of Undermountain was Nargast Kanir, the Black Ghost. He and his apprentices explored the ruins and laid claim to many areas. Over the next thousand years they populated these areas with various monsters, magical experiments, numerous portals and traps. Around the 337th year of the third era the City of Kaniros started exiling convicted felons to the depths of Niikazad.

Various criminal groups used portions of the dungeon as their headquarters as do followers of Daedra. Nargast's faked death in 3E 406 and the earthquake that accompanied it altered terrain and also upset the balance of power among the various groups. Many of the numerous portals in the ruins were destroyed, cutting off entire levels. Other portals were warped and seemingly granted access to previously unknown levels.

Entrances and Exits
The halls of Niikazad were linked to the surface world in many ways, both physical and magical. NArgast used his network of portals to bring in monsters from all across Nirn to restock his dungeon. He also used portals to draw adventurers into the deeper regions, rarely explored, and to give the occasional lucky adventurer an unexpected escape.
 * Castle Kanir This passage corkscrewed down from the cellars of Castle Kanir to Boneport, bypassing the first two levels.
 * Seacaves  This linked the Blue Coast on the western flank of Mount Kanir with the river Malgoth by means of a set of hoists. Malgot is a subterraneon river in Niikazad that ran deep under Kaniros, the town of Boneport was found at it's banks..
 * Gaping Gate Inn Built atop the ruins of Niishan, The Gaping Gate inn contained the primary entrance into Niikazad: a large well that dropped down into Niikazad's Dungeon Level. Secondary entrances were found in the inn as well, including a link to the inn's less well known "wee" well and a passage leading out of the Gaping Gate's cellar