The "L" -- Chicago's Elevated Trains
This is at the northeast corner of State Street and Van Buren Street, looking west. The red building on the left is the Chicago Public Library -- out of view are the gargoyles around the top of the building.

The L is one of the characteristic features of Chicago, even though it's just a part the Chicago Transit Authority, along with the city buses. There is a section that's not elevated though -- the Red Line that runs along State Street is a subway.

The train above is on a route that circles central downtown Chicago. Because of this route, the area inside is the district of Chicago called "The Loop".