The industrial city of Garz was a company town, initially built to support the vast strip mining operation that took place on the planet of Rugen. The primary products of Garz are a collection of processed and refined metals, mainly Titanium, Aluminum, Iron, and a collection of rarer metals that were all extracted from the coarse sand. The mining operation itself took advantage of a vast mineral desert on the southern continent, but that mineral richness also made the local environment incredibly harsh to work in, to say nothing of survival.
So the city of Garz was established north, across the shallow equatorial ocean. Fortunately an interstellar civilization had easy transportation technology, and the raw materials harvested could be easily brought to the city for processing. The largest part of the city was the smeltery and fabrication plant, that took the raw materials and processed them into ingots, parts, and structural components. The rest of the city is spaced out away from the plant in order to give the heavy industrial processes the space they need. What other industry and operations that exist are tailored to supporting the worker population, as Garz is the largest single population on the planet.
A while back when I was playing a D&D game with friends, I played around with sketching a few different cities and towns as part of building out the setting. Garz was one of three that I put together, and the only one of the three that was referenced in the writing, mentioned in passing in Turn 114.