Some of the action in Star Wars - Coruscant Nights I: Jedi Twilight takes place in the Factory District. It's noted that this place is on the opposite side of the planet from Galactic City, where the Jedi Temple (and Senate, etc) are based.
A few minutes later, he realized Xizor's destination: the Antipodes. The area of the globe diametrically opposite to Imperial City. The area known as the Factory District.
A chill ran the down on his arms and neck. The Factory District was,
according to all accounts, one of the most dangerous places on the
entire planet. Centuries ago, it had been a thriving industrial center
that sprawled over most of the northeastern quadrisphere, near the
equator. But economic downturns and the streamlining of production
techniques on Metellos, Brentaal, Duro, and other Core worlds,
together with the lifting of trade sanctions and political lobbying in
the Galactic Senate, had resulted in most of the manufacturing and
engineering contracts being moved offworld. As a result, except for
isolated areas where automated minimal production of some goods still
took place, thousands of square kilometers had become forgotten, and
eventually cut off from utilities, supplies, and communications. The
area was a wasteland now, more lawless and dangerous even than areas
like the Southern Underground or the Invisible Sector. By day,
primitive tribes of humans and other species roamed the dilapidated
structures; by night the ruins were prowled by Cthons, stratts, and,
some averred, by nameless horrors unknown on any other world.
In the main canon the farthest we see from the centre of Galactic City (excluding space shots) is about a two or three 'sectors' away from the Temple district, when Dooku and Palpatine visit The Works in Sector 943.