Why are we drawn to certain cities? Perhaps because of a story read in childhood. Or a chance teenage meeting. Or maybe simply because the place touches us, embodying in its tribes, towers and history an aspect of our understanding of what it means to be human. Parıs is about romantic love. New York means energy. And Berlin…? Berlin is all about volatility and this walk -- with best-selling author Rory MacLean -- takes you into the heart of Berlin's tumultuous history, from Kaiser to Hitler, Kennedy to national rebirth.