Today, the Queen of the United Kingdom's Crown Jewels are safeguarded in the Tower of London’s Jewel House, under the watch of armed guards. But during World War II, select gems from the priceless collection were stored in a biscuit tin and buried on Windsor Castle’s grounds, according to Business Insider.
The unorthodox hiding place was recently revealed in a new BBC documentary, The Coronation, which looks back on Queen Elizabeth II’s rise to the throne in 1953. British news commentator Alastair Bruce, who interviews the Queen in the hour-long special, says he stumbled across the story while perusing once-confidential letters between royal librarian Sir Owen Morshead and Queen Mary, the mother of King George VI and grandmother of Queen Elizabeth.
Fearing that the Nazis would seize the royal jewels, George VI ordered the treasure-filled tin to be buried underneath a secret emergency castle exit. The jewels—including the Black Prince's Ruby and St. Edward's Sapphire, both taken from the Imperial State Crown—were accessible only through a trapdoor.
The freshly tilled earth was a chalky white. To avoid notice from the German Luftwaffe, tarps were used to conceal the dug-up grounds at night. The Nazis weren’t the only ones left in the dark: Princess Elizabeth, then 14 years old, had no idea where the gems were buried, although she did know they’d been hidden at Windsor.
This story—along with other musings on royalty from Queen Elizabeth—is shared in The Coronation, which airs on the Smithsonian Channel on January 14.
[h/t Business Insider]