A 500-year-old sketch by Leonardo da Vinci has led to the remarkable discovery of hidden tunnels beneath Sforza Castle in ...

Archaeologists used Leonardo da Vinci's sketch to uncover secret tunnels beneath an ancient castle, revealing a hidden historical mystery with the help of modern technology.

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.

One of the most prominent rumors surrounding the over 575-year-old fortress has long been the existence of secret passageways beneath the grounds originally hinted at by Leonardo da Vinci.

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

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

Sketches in Leonardo da Vinci's Codex Forster I appear to show tunnels leading from the castle. Ground-penetrating radar appears to have found them, centuries later.

Leonardo da Vinci's secret underground tunnels discovered after 500 years A series of underground passages have been found under Sforza Castle in Milan by experts at the city's Polytechnic University.

The artworks of Leonardo da Vinci are vast and storied. “The Last Supper.” “The Vitruvian Man.” The “Mona Lisa,” for goodness sake. But even amongst such a storied and well-studied body of work, there ...

By Taylor Nicioli, CNN (CNN) — Leonardo da Vinci excelled in the fields of art and science, but the Italian polymath was also a highly skilled expert in military structures and defensive systems ...