PARIS, FRANCE - MARCH 18:  Britain's Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge visit a 'Les Voisins in Action' event highlighting the strong ties between the young people of France and the UK at the Trocadero in front of the Eiffel tower during an official two-day visit to Paris on March 18, 2017 in Paris, France.  (Photo by Laurent Vu - SC Pool - Corbis/Corbis via Getty Images)