Once only indicated through a sketch by Leonardo da Vinci from around 1495, concealed passageways have been discovered underneath the Sforza Castle in Milan, Italy.

Researchers have discovered hidden tunnels beneath Milan’s Sforza Castle, which may have been used for military defense, possibly connected to Leonardo da Vinci’s designs. The underground passageways uncovered include a previously unknown tunnel and structures suggesting real-world influence from Da Vinci’s architectural sketches.

A team at the Polytechnic University of Milan uncovered secret tunnels beneath Sforza Castle, potentially linked to Leonardo da Vinci's designs.

Researchers in Italy may have uncovered underground tunnels beneath Milan’s Sforza Castle that were once only known through a sketch by Leonardo da Vinci, according to a report by CNN.

Scientists have finally uncovered hidden network of tunnels beneath a medieval castle, which were originally sketched by Leonardo da Vinci.The discovery was made during a project to digitize the underground structures of the 15th-century

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

A series of underground passages have been found under Sforza Castle in Milan by experts at the city's Polytechnic University.