In 1773, when the Jesuit order was abolished, an unprecedented hustle and bustle took hold of Prague’s Clementinum. The Jesuits, believing they would one day return to their grand residence, decided to hide the most valuable parts of their fortune from the official commission. Legend tells of a poor mason visited one night by unknown men in black cloaks. With blindfolded eyes, they brought him into the deep Clementinum cellars and commanded him to wall up a secret room filled with gold and valuables so perfectly that no one would know a corridor had ever been there.

The mason did his work honestly and was rewarded with a handful of gold coins. However, when word later spread that the Jesuits had indeed left and the commission found only a fraction of the expected wealth, the mason’s conscience spoke. He went to the town hall and described his night journey, but in the labyrinth of the Clementinum underground, he was never able to find that spot again. Many believe that the Jesuit treasure—leather-bound books, golden monstrances, and chests of coins—still waits behind one of the thick walls for its rediscovery, protected by the silence of the mason who never returned.