From the Buckingham Palace secret tunnels to the hidden passageway linking St James’ Palace to one of Mayfair’s ritziest bars, discover the royal family’s secret escape routes at Windsor Castle, Kensington Palace and more From the Buckingham Palace secret tunnels to the hidden passageway linking St James’ Palace to one of Mayfair’s ritziest bars, discover the royal family’s secret escape routes at Windsor Castle, Kensington Palace and more