I find places like this interesting. I have lived by this place for years. I have driven over it a million times. These places are always justy out of sight from most of us but we pass them everyday. It's good to go exploring.! Thanks Maria.
Chicago has a labyrinth of underground roadways. Along those routes, the large buildings' loading docks are accessed via these underground streets, but also at rush hour they are major routes into and out of the heart of the city. During rush hour, it's scary during the day! Get out of the way or stay topside. Homeless people are very creative with carving out living space down there, too. Very interesting.