The Factory District, which later became known as the Feral City, was a district located on Coruscant. It was situated in the Antipodes, which is the side of the planet directly opposite Imperial City. Reportedly, it was the most perilous location on the entire planet.
Many centuries prior to the Clone Wars, this area was a flourishing industrial hub. However, the growth of industry on nearby worlds such as Metellos and Brentaal led to cheaper off-world production. The facilities were abandoned, and the district transformed into a refuge for criminals and subterranean creatures. Rumors even circulated about packs of feral droids patrolling the Factory District.
The relatively small buildings, none exceeding fifty stories in height, gradually deteriorated, along with the roads and other infrastructure elements. Due to the area's isolation, the Falleen Black Sun Vigo Prince Xizor established a clandestine laboratory where his scientists and technicians dedicated themselves to perfecting the technology for a human replica droid. Xizor employed a group of mercenaries known as the Salissians to get rid of the feral droids, but the droids proved too dangerous to control. Subsequently, the droids attacked the Vigo's lab, obliterating all research and personnel.
During their quest to locate 10-4TO, Den Dhur and I-5YQ discovered a substantial reactor leak occurring beneath the Factory District. They concluded that this leak was the cause of the droids' murderous behavior. The Sullustan, his droid, and former Jedi Jax Pavan managed to escape the area, but the reactor then overloaded and exploded, leaving behind an eighty meter wide crater and turning a significant portion of the Factory District into radioactive debris.
The narration also refers to it as "the Antipodes," which is the real-world term for the point on the Earth's surface diametrically opposite to a given location. However, because its use here was capitalized, and the antipodes of the Factory District was Imperial City, it may be that this term had a special significance in this instance.