Zygerria

The planet experienced success during the thousands of years the Zygerrians maintained their slave labor industry, but after the Jedi cracked down on the slaving operations, it faded from glory. Slavery was brought up again when the Zygerrians collaborated with the Separatists during the Clone Wars.[4]

During the Zygerrian Slave Empire's height, the population had fortresses and cities built on top of the mesas scattered throughout the planet, using slave labor.