Steps

Most Edinburgh natives have climbed the Scotsman Steps at some point; they go from Market street up to the North bridges and the most famous thing about them used to be how much they smelled of wee.

But a few years ago they replaced them with a work by Martin Creed (called Work No. 1059) that used 104 different types of marble (one per step).  

They've kept them cleaner, but it's still well-used and a bit dirty(though not a toilet any more).  I like the dirt - they're dirty because thousands of people climb hem every day.  I like the idea of them all climbing through a work of art.