The hidden medieval world buried beneath a castle
At first sight, there is little clue to the secrets that lie beneath the Château de Brézé in France. Below the surface of this impressive castle lies a deep network of tunnels and rooms that form one of Europe's largest underground fortresses.
Much like the billionaires of today, the lords of this castle carefully constructed themselves a medieval 'doomsday bunker' to provide themselves with shelter and protection in the face of invasion or disease.
Video by Mathieu Orcel and Augustin Muniz
