Terok Nor orbiting Bajor.
In the mirror universe, "Terok Nor" was a space station built under the authority of the Klingon-Cardassian Alliance in orbit of Bajor. In 2370, the station was the command post for Alliance authority throughout the Bajor sector, under the command of Intendant Kira Nerys. The station also served as a processing center for uridium ore mined from Bajor; the processing facilities were manned by Terran slaves. Terok Nor still orbited Bajor in the Mirror Universe because the wormhole was still unknown there.
In 2372, the Terran Rebellion wrested control of the space station away from the Alliance. The Alliance, determined to recapture the station, sent a fleet of ships under Regent Worf to fight the rebels. When they arrived, the rebels had completed their Defiant which was based on schematics for the Defiant in the primary universe. The Alliance fleet was defeated and Terok Nor remained a base of operations for the Terran Rebellion for at least the next three years.