- Main article: Molag Mar Locations
The Molag Mar Underworks is home to the city's sewer system. The dark tunnels and putrid waters span beneath the city. It is a dangerous location containing slaughterfish, rats, a corprus stalker, and the remains of an Imperial Legion knight.
There are two entrances to the underworks via trapdoors in the city proper: one in the northeast corner of the city, and another in the southwest. The remaining four entrances are via trapdoors in the canalworks.
Two sewage canals run east-west, along the northern and southern sections of the underworks. There are ramps leading out of the water near the footbridges should the Nerevarine fall in.
Two tunnels connect the north and south sewage canals. The western tunnel contains a dead adventurer, the remains of an Imperial warrior and Legion knight who met her fate among the sewer's filth and moss-lined walls. She has a full set of armor, shield, melee weapon, gold, lockpick and probe, all leveled.