LETTERKENNY, IRELAND - MAY 25: Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall take in the surroundings from the boathouse roof with their guide Mr Dave Duggan, Divisional Manager Parks and Wildlife Service (L) as they visited Glenveagh Castle on May 25, 2016 in Letterkenny, Ireland. The royal couple are on a one day visit to Ireland having spent two days across the border in Northern Ireland. It is their first trip to Donegal. (Photo by Clodagh Kilcoyne - WPA Pool/Getty Images)