Somewhere in the late 18th century, when people of Paris started having some health issues with the overflowing cemeteries in the city, a decision was taken to transfer their contents to an underground site.
The remains were transferred to an unground tunnel network, which now holds the remains of over 6 million people.
Yes, these are real skulls and bones.
I wonder whom does she guard in a place like this
Some famous (or infamous) characters from history who call the catacombs their final resting place include Jean-Paul Marat, one of the Revolution's most radical voices, and Maximilien de Robespierre, an influential figure during both the Revolution and the subsequent Reign of Terror.