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.
The reason that it was still in orbit around Bajor was that in that universe, the Wormhole had not been discovered.
In 2372, the Terran Rebellion wrested control of the space station away from the Alliance. The Alliance, determined to recapture sent a fleet of ships under Regent Worf to fight the Rebels. When they had arrived, the rebels had completed their Warship Defiant which was based off of 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.