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.

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

Italy’s famed Sforza Castle is a focal point for historians, architects, and art lovers—as well as a source of many legends. 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.

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.