An underground tunnel network long rumored thanks to drawings by Leonardo da Vinci under Milan’s Sforza Castle are proven to exist. Ground-penetrating radar and laser scanning revealed that the historic passages made famous by a Leonardo da Vinci drawing is just one of multiple tunnel sections.

Archaeologists Blown Away After Finding Secret Tunnels That Da Vinci Had Drawn Over 500 Years Ago Researchers from the Polytechnic Institute of Milan visited the site of Italy’s famed Sforza Castle as part of a doctoral thesis and conducted a technological study.

A technological investigation at Sforza Castle found that it does in fact hold underground passages once described by Leonardo da Vinci.

For centuries, whispers of hidden tunnels beneath Milan’s iconic Sforza Castle have intrigued historians and treasure hunters alike.