What was once percieved as a lair only intended for mutated teenage reptiles skilled in various styles of martials arts, the vast underground sewer chasms has become a notable place for many who have very unique reasons not to walk around on the upper streets in wide view of the public. Many Naturalists use this huge network of long tunnels to travel around after they've scored a big heist. Those who venture down underneath this area always use a map to guide them in some way. The sewers are so vast and go under so many parts of the city that one can easily become lost within the twists and turns of the concrete tunnels.

Some even choose to make temporary dwellings within these networks, creating an underground sub-culture. Everything from Naturalists trying to hide out against the patrols of FPE agents, to Techlightens setting up their next terrorist act. Many drug and illegal firearm deals also tend to go down in these sewers, as it is an area much like Layer 5 that rarely ever gets monitored by FPE cameras.

Compared to Layer 5 though, the Sewers are much safer to travel along. Though some times intense fire fights will occur here, mainly in the rare instances when the FPE does decide to chase after those who try to travel underneath here.