It’s a big, beautiful world out there. Please enjoy it responsibly. The latest prompt from the Big Book O' Photo Prompts is: Color! Any of them. All of them, I suppose. So it's time to check out a bit of street art. Built into the undercroft of the Queen Elizabeth Hall on London's thriving South Bank district is a decades-old skate park. Built more than 40 years ago, the skate park has become a 24-hour creative space, used not only by skaters, but as an open-air workout space by other athletes, by photographers, and by artists. The Undercroft is also a graffiti tunnel, covered in an ever-changing mural of street art. Like London, it is vibrant and clever and diverse. Nevertheless, one really ought to pay attention to where one sits.