History is swarming with lost treasuresfrom Aztec gold concealed throughout the Spanish conquest to the Ark of the Covenantwhich disappeared throughout the damage of Jerusalem over 2,500 years earlier. In his book, “The Museum of Lost Things: True Tales of Fabled Treasures, Legendary Cities, and Mythical Creatures That Vanished From History” (National Geographic Partners, LLC, 2026), author Sam Kean analyzes all things lost to time.

In this excerpt from the book, he takes a look at how the burial place of Genghis Khanprobably the most effective ruler in history, has actually stayed concealed for almost 800 years and counting.