Skool

The city's elementary school, spelled "Skool" for unknown reasons, is where Zim, Dib, Gaz, and other children come to receive their education (Zim's intentions being different, in that he yearns to know enough about the planet Earth to weaken and conquer it). The Skool itself is a dreadful establishment, with several harsh teachers and staff, hazardous food, inadequate funds and resources, and filthy restrooms. However, the technology is extremely advanced, in that robots, flying cameras & platforms, and machines of various kinds are used.

The Skool's boiler room ends up being the destination for one of the scattered chaos emeralds during the "Dimension" saga; Calvin's newly-created Emerald Radar is able to lead them to their target object, but before they can obtain the emerald, they are promptly ambushed by a squadron of Egg Robos. The ensuing fight evidently causes the gas pressure in the room to rise, forcing everyone to flee the premises—except Shadow, who opts to stay and search for the emerald, while battling the oncoming Egg Robos. As the impending explosion draws near, Shadow at last retrieves the silver chaos emerald and uses Chaos Control to slow down time, which allows him to successfully shut off the gas and prevent the facility's destruction.

Zim later returns to the Skool after his defeat in the Mushroom Kingdom, where his classmates and teacher are observing the War Above Earth. Zim realizes that the Irken Armada is assisting the alliance in their struggle against the Death Egg, at which point he decides to rush out and join the battle.