British Crown Jewels
From Tardis Wiki, the free Doctor Who reference
The British Crown Jewels were part of the ceremonial regalia of English monarchy. They were kept in the Tower of London. (COMIC: Secret of the Tower)
In the 1970s, Mike Yates of the UNIT said that getting a hold of the suspicious waste from the Global Chemicals would be have been difficult like stealing the Crown Jewels. (TV: The Green Death)
Missy, using her vortex manipulator, was able to break into the Tower to steal the jewels. The Twelfth Doctor entered the room, barely missing the chance to stop her from again jumping into the Time Vortex. (PROSE: Dr. Twelfth)
