Seeing all the other pictures in your gallery this location seems to have many interesting spots and objects that make it an ideal place for some grungy photography. By looking at your other images I also have to say that in my opinion this picture is one of your weaker ones taken at this place. Let me explain why.

Your title "Sit Down" suggests that the chair is supposed to be the main object. However, there are so many other objects that draw the viewer's eye away from the chair. Especially that yellow helmet is very distracting. This could have been fixed by choosing a black and white color scheme and a narrower depth of field with a blurred background (or even darken the background to give it a grungier feel). Then the chair would stand out more.

The fact that the chair is right in the middle of the picture does not emphasize its importance in my opinion. I think placing it in the center makes the picture look rather ordinary and therefore boring. Try to put it off-center or "orbit" it from different distances to find a more special and interesting perspective (how about placing those glasses somewhere and take the chair through them so that you have them as a natural frame? ) You could also try to take the shot during dusk or at night with a flash to add some extra spookiness.

What I do like about the image is the graininess, which makes the picture look even dirtier.

To sum up, this is a great place and with a better perspective and colors you can really get some killer pictures there.