As a non, Australian, I didn’t know wittenoom, but I’m pretty sure I know of it from the old videos of asbestos shoveling competitions that went around a few years back.
I think the smallest Australian town I know is oodnadatta, but I don’t know why I know it. I also had to look up if “nullarbor” was a city, or just a place name, so idk if that counts.
In case you aren’t American, that line is the Great Plains. It’s basically the dividing line between where it historically gets enough rain to farm, and where it’s dry enough that farming gives way to ranching.