The penthouse of the Megakat Tower. It was an extremely luxurious room overlooking the city, situated on a raised platform at the very top of the 300-story building and accessibly only by elevator. It included, among other things, a scale model of the Megakat Tower itself located by the elevator.
Dr. Viper used it as his base of operations when he took the tower over and started growing his spore pod inside of it. It was completely destroyed when the spore pod burst the roof and then the SWAT Kats dropped a tank of super rocket coolant onto it, destroying the top few floors and freezing the entire building.
Later, the Megakat Tower was rebuilt at great expense. When the queen Ci-Kat-A needed a high place in which to lay its eggs, Dr. Street directed it to the tower penthouse. Here, it laid its eggs. The penthouse was again destroyed, this time by the Enforcers, who sprayed it with flamethrowers from their helicopters to destroy the Ci-Kat-A eggs. The flaming penthouse detached from the top of the tower and fell onto the queen Ci-Kat-A, crushing it and saving Mayor Manx, Mr. Young and their chauffeur (and covering the three in alien bug guts).