Welcome to one of the most recognizable street corners in the world. You are standing where Friedrichstraße meets Zimmerstraße, right on the district border between Mitte and Kreuzberg. Today it is a busy junction with traffic, visitors and cameras. For nearly three decades it was the best known official crossing point between East Berlin and West Berlin. The name sounds like a spy novel, and it practically became one. The crossing turns up in thrillers and spy stories, from The Spy Who Came in from the Cold to the James Bond film Octopussy. But the name began as simple administrative shorthand. The Allies labeled their checkpoints with letters, and the one in the Friedrichstadt area was Checkpoint C. In the NATO phonetic alphabet, C is Charlie. As we go, I will take you through the night the world watched tanks face each other, the stories of those who tried to cross the border, and what stands here now. Take a moment to look at the junction itself. The people who walked these pavements in the early 1960s saw it very differently from the way you see it now.