I'm not sure I'm as wild about this one as the power station or jetty ones (but perhaps only because they were SO good), but I still like this one a lot. The pure, simple lines make for a great composition base, then (much as I normally despise graffiti in general and tags in particular) this one breaks that up; it gives a focal point to suggest that the place isn't really completely abandoned as the rust might suggest but that people are still here from time to time. Similarly the greys of most of the shot are offset by the one patch of reddish brown.
