The L is the elevated train system in Chicago and many films have been filmed underneath it’s tracks, including some scenes in Batman, The Dark Knight. Here’s the L under Kimball on the brown line. I worked close by a few years ago!

The Brown Line to Kimball Aboard one of the trains of the Chicago L, the elevated and underground train network in Chicago. I think this was taken near the south end of the Loop, possibly around the corner from the library. The last time I was in Chicago I took the L for nostalgic reasons…