Obviously a far younger city, but when I moved to seattle, satellite view on maps was just starting to be a thing, and you could spot all of the areas that were

Obviously a far younger city, but when I moved to seattle, satellite view on maps was just starting to be a thing, and you could spot all of the areas that were interesting to go to versus residential neighborhoods by the way the light reflected off the roofs. Lighter color along a street usually meant older, flat-roofed buildings where the market streets of the original towns were.