Foul smells assail the adventurers' senses as they make their way down into the warrens below the city. All urban waste passes through these tunnels, as well as a significant subset of all crime. Revolting creatures live in the waste, lurking below the opaque liquids. These sewers were once a marvel of engineering, and to an extent they still serve their purpose well. The skillful craftsmanship still shows through the grime in places, and the torch holders in the wall are made of elegantly curling cast iron. However, time and the increasing population of the city above have overtaxed the aging system. When it rains, the water turns the tunnels into floodpaths.