Potsdamer Platz

This guide to Potsdamer Platz in Berlin starts in 1924, when a single policeman was given the job of directing Europe's busiest crossroads alone from a glass tower in the sky, until it automated into the continent's first true traffic light in 1926. It follows the square through Allied bombing in 1943, the Berlin Wall cutting straight through it in 1961, and the twenty-eight years it spent as the city's widest death strip, including a sealed ghost station where trains rolled past without stopping. Look for the Weinhaus Huth, the one building from that era still standing on the square today.