Chicago is a city of underground tunnels. Some are used more than others, and some have been completely abandoned (evident in the highway collapse last year). The one in the photo below is an underground passageway that connects the city to the lakeside path used by millions of Chicago residents during the warmer months (myself included). But, during the winter the walkway is quite. A weird feeling when you're so used to fighting your way down the stairs and trying to dodge bicyclers and rollerbladers as you make your way to the path.
In PS I changed the hue to green to give it the "eerie" feel that I was after. I also added some contrast to bring out the puddles on the ground and the graffiti on the wall.
The black backround doesn't really help much but it's late and I've got an early call in the morning.