The City (Zim's dimension)

The city in Zim's dimension is a large, generic, heavily-populated metropolis on Earth, consisting of many buildings, skyscrapers, and a suburban neighborhood where both Zim and Dib reside. Also located within the city are the local Skool, shopping mall, Cess Pool, and apartment complexes.

In "Dimension Mix-Up," two chaos emeralds are transported into different areas in the city—specifically, the Cess Pool and the Skool—and both Doctor Eggman and the alliance of heroes come searching for them; while half of the alliance ventures into the city sewers to find the Doctor, the other half searches for the emeralds and successfully acquires both at each location, albeit after two different struggles against piranha plants and Egg Robos. In addition, an intersection suffers an explosion from below as the sewer chase occurs, and Zim and GIR later confront Dib and Doctor Eggman in an alleyway before more Egg Robos attack the alliance in the city streets. The battle is later taken to an old convention site in a local park, where the team regroups and eventually escapes by Shadow's Chaos Control.

During the City Escape, Bill the paranormal investigator discovers what strange events are occurring in the city, and explores each scene shortly after each event has ended; after learning of Dib's involvement in these matters, Bill searches for Gaz and finds her on a highway, walking and playing her video game. They both leave the city behind to follow both Dib and Doctor Eggman through the alternate dimensions, and then later return to the city following the War Above Earth, as the Doctor is placed in federal custody by Bill.

Later on, in "Dimension Takeover," Zim and Dib engage in physical combat in the city streets to settle their feud, following one of Zim's usual schemes—until they are interrupted by the sudden arrival of the Xevian fleet, led by Tak, come to re-conquer the planet. The city itself is brutally wiped out by the Andor Genesis mothership, in spite of Dib, Bill, and a Yoshi militia's efforts in defending it; many lives are lost in the attack, and survivors are evacuated, save for the Swollen Eyeball Network (Dib and Bill included), who remain in hiding to learn of the invaders' origins and ultimate motives. The smoke-filled wreckage of the city is where Sonic and his friends arrive in an Egg Carrier to rescue Zim, who was abducted by Tak, and where Xevian SOL towers later begin emerging from under the ground (signifying that the area has been conquered) as a battle between the Xevians and the fraction of the alliance ensues—ending in the alliance's escape via Dib's watch.

After the Xevians are ultimately defeated, the survivors of the City Invasion return, Gaz and Professor Membrane included; the city is repopulated and eventually restored by the civilians, with the SOL towers and all other remnants of the Xevians' takeover removed.