After visiting the Tate Modern this afternoon I walked across a bridge over the Thames River and looked down to discover this, the skateboard graveyard. After doing a bit of research I learned that this is where skaters dump their destroyed boards after damaging them at a nearby skatepark. I also was able to find an online message board where you can link individual boards to the story that lead them to this gravesite, although most are just filled with skaters trolling them with outlandish stories, which makes it even better, in my opinion.