KATOOMBA, AUSTRALIA - APRIL 17:  Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge pose for a photograph at Echo Point with the Three Sisters Rocks in the background on April 17, 2014 in Katoomba, Australia. The Duke and Duchess of Cambridge are on a three-week tour of Australia and New Zealand, the first official trip overseas with their son, Prince George of Cambridge.  (Photo by Arthur Edwards- WPA Pool/Getty Images)