I was walking down Armitage Avenue in Bucktown today, and couldn’t help but notice that a lot of the houses are built on lots that are several feet (five or six?) below the level of the sidewalk and the street. After noticing that, I remembered seeing the exact same setup along some of the side streets in Chinatown, the numbered streets that shoot off to the west from Wentworth.
What is the purpose of this? Did they deliberately lower the residential plots, or did they raise the street? Is there some architectural reason? Or geological, or technological, or historical, or just plain aesthetic reason for it?