Researchers may have found the hidden tunnels beneath a castle in Milan that Leonardo da Vinci sketched in 1495.

Pictured is Sforza Castle in Milan. A new geophysical survey ... Some of these, the researchers say, can be linked to secret military tunnels that can also be seen represented in Leonardo designs.

An underground tunnel network long rumored thanks to drawings by Leonardo da Vinci under Milan’s Sforza Castle are proven to ...

Italy's Sforza Castle includes a underground passage that linked the Duke of Milan to his wife’s tomb.