City Cess Pool

The city's Cess Pool in Zim's dimension is a toxic waste facility for both sewage and trash alike. The Cess Pool is extremely hazardous, and anyone who were to fall in would slowly melt in sewage—hence the urgency in Luigi's efforts to pull Calvin and Knuckles out of the depths, during the Cess Pool Quest in "Dimension Mix-Up." Its structured platforms prove to be very weak, in that they eventually begin collapsing beneath the alliance's feet (perhaps because of the piranha plants), forcing them to quickly vacate the scene. Shadow manages to avoid the toxic sewage as he uses Chaos Control to teleport and grab the red chaos emerald that had been transported to the Cess Pool in the first place. After Luigi defeats the attacking piranha plants and rescues Calvin and Knuckles, the group is able to quickly flee the Cess Pool out of sheer relief.