Skullport

Skullport, also known as the Port of Shadows, is a subterranean city located far below Waterdeep, within the 3rd level of Undermountain known as the Sargauth Level. While rumors of this subterranean domain of villainy persist throughout the surface world, few of its inhabitants have any knowledge of any points of entry.
Built on an ancient Netherese ruin, within an immense subterranean cavern, the shadowy port is a dark reflection of the City of Splendors above. Its structure is built in three tiers, interconnected by narrow catwalks and rickety scaffolding. Creaking houses perched on stilts are haphazardly built in a dense network that form a shantytown.
Skullport may be the safest city in Undermountain, but it doesn’t have much in the way of competition. More to the point, Skullport is the only city in Undermountain. Its streets are rife with brain-sucking mind flayers, its skies (such as they are) are patrolled by half-mad flameskulls, and its dark alleys are prowled by bugbears, duergar, drow, and all manner of unsavory folk. Still, when you’re an adventurer deep in one of the deadliest dungeons in all of Faerûn, even the dour and dangerous silhouette of Skullport is a welcome sight.

Government

As of 1479 DR most control over day-to-day activities was managed by gangs such as the Lowfellows or the Mandible. however, Within a few decades, Skullport has completely come under the domain of the being known as Xanathar and become the base of operations for his thieves' guild.
However, the Skulls of Skullport, magically transformed remnants of the original Netherese mages who settled in the cavern, watch closely over trade within the town. Any activities that interfere with the town draw the attention of the Skulls who impose seemingly random punishments for minor infractions and enslave or destroy offenders for serious crimes.

Type

Slum