PARO, BHUTAN - APRIL 15:  Catherine, Duchess of Cambridge takes part in a trek to the Tiger's Nest Monastery on the second day of a two day visit to Bhutan on the 15th April 2016 in Paro, Bhutan. The Royal couple are visiting Bhutan as part of a week long visit to India and Bhutan that has taken in cities such as Mumbai, Delhi, Kaziranga, Bhutan and Agra.  (Photo by Danny Martindale/WireImage)