Steel first, skyline later
Zone an ore field and a rail spur, and the district takes it from there. Smelters raise their stacks, yards and warehouses fill the gaps between them, and the freight line keeps stretching until it reaches the port on the far side of the map.
Everything else in the city is downstream of this one district. Power, parts and building material all start here — and so does the smoke that decides which streets nobody wants to live on.
A run usually opens here. You pick a seam, drop a smelter beside it and run a spur to the nearest line, and the district starts paying for itself before the first residential block is zoned. Output is deliberately lumpy at this stage: one stalled furnace is enough to stop a build queue three districts away.
Freight is scheduled, not automatic. Yards hold a limited number of wagons, routes can be re-timed between shifts, and a route left on its default timetable will quietly strangle the port once the city doubles in size. Most of the mid-game tuning in this district happens on that timetable rather than on the factory floor.
Smoke drifts with the weather, soil load accumulates under the plants, and both show up as falling land value around the district. Filters, electrification and relocating the dirtiest processes are all available — each of them trading immediate output for somewhere people are willing to live.
