Each of the city-states of Achaea, except Eleusis, possess sewers beneath the city streets where rats dwell in abundance, often along with shady sewer thugs. More intrepid adventurers are known to brave the stinking depths to hunt for rats to line their pockets with gold from the cities' ratmen, or to try their fists, swords, and spells against the thugs there. Aside from the usual thugs and rats, a few sewer systems have unique residents all their own.
Hashan's sewers play host to the infamous Thieves' Guild, headed by the notorious Kriegan, Prince of Thieves. The hall of the Thieves' Guild is guarded closely by Big Bubba Bingham.
The sewers of Cyrene are populated by seven-foot blood leeches which are known for multiplying spontaneously, often at the most inopportune times. Their origin is unknown. These sewers empty into Lake Muurn.
Mhaldor's sewers are quite possibly the most dangerous of any sewers on Sapience. Adapted from the tunnels dug by Moghedu with the intent to sink Mhaldor during the Moghedu War, these sewers are still populated by scattered groups of Mhun scouts whose orders are to attack on sight. Bertram, the sewer worker also resides here. Travelling deeper yields a monstrous geryas that has taken up residence, and in the deepest reaches a planar anomaly has left a deadly frost daemon chained to an interplanar stretch of darkness. These sewers are drained by the mouths of stone gargoyles hewn from the mountainside.