I had never talked to the walls before that day. But one cold morning in Berlin, I stood in front of an ordinary wall with a mural painted on it, and spoke to it. It told me a myriad of stories that it had heard from many visitors, seen for itself, been told by the walls nearby and had heard from the skies above. I listened intently, and I vowed to tell these incredible tales to the world. Over the following months, I endeavoured to retell them as best I could, from what I could remember and how I heard them told. It took hours hunched over a notepad with pen in hand, dozens of ink cartridges, hundreds of cups of coffee, and endless frustration and work, but eventually I told as much as I could. And so I present them to you, dear reader, so that you may feel them as I did standing on German streets, talking to the walls.