BERLIN, GERMANY - JULY 21:  Catherine, Duchess of Cambridge, and Prince William, Duke of Cambridge (not pictured), arrive at Berlin Hauptbahnhof main railway station before taking a train to Hamburg on the third day of the royal visit to Germany on July 21, 2017 in Berlin, Germany. The royal couple are on a three-day trip to Germany that includes visits to Berlin, Hamburg and Heidelberg.  (Photo by Sean Gallup/Getty Images)