Leonardo da Vinci is still making history, more than 500 years after his death.
One of his sketches recently led a team of experts to discover secret tunnels underneath the medieval Sforza Castle, in the heart of modern-day Milan. It was built in the 15th century by Francesco Sforza, Duke of Milan and in 1495 he hired da Vinci to decorate the castle, who frescoed several rooms.
Live Science reports that it was around this time that the Renaissance polymath also sketched defensive structures that looked similar to the Sforza Castle, including secret passageways that weren’t known to exist, until now.
Using this historical knowledge as well as ground-penetrating radar and laser scanners, the team from the Polytechnic University of Milan matched da Vinci’s sketch to the castle. “This passageway is immortalized in Leonardo’s drawings, and has long been the subject of legends and considerable speculation,” a press release from the university reads. “But now, thanks to technology, it seems that its existence can be confirmed.”
The passageways are said to be part of early military defences, and researcher Francesca Biolo told Live Science they’re likely just the beginning when it comes to Sforza Castle’s hidden architecture.