I happened upon this article in the Oddly Enough section of Reuters on my Reuters Newspro iPad App some time ago. Unfortuantely, the hilarious picture that was included in the iPad app is missing from the archived article. So, allow me to describe it!
It was a penis painted on one half of the draw bridge such that it became “erected” whenever the drawbridge lifted. This is the only picture I could find from this article after doing a Google image search.
Without a doubt, it took a lot of balls to erect this work of art. Those underground Russian graffiti artists deserve a lot of praise.
There is more about this “phenomenon” here.