Sforza Castle: A Renaissance Fortress and Its Hidden Depths
Located in Milan, Sforza Castle (Castello Sforzesco) underwent a dramatic transformation in the 15th century under the orders of Francesco Sforza, Duke of Milan. Rebuilt into an imposing military fortress, the castle features towers, courtyards, and grand halls—many decorated with exquisite frescoes. In 1494, Sforza’s successor, Ludovico, brought in Leonardo da Vinci to add his artistic magic to the fortress. During this period, Leonardo documented a network of underground tunnels within the castle in his Codex Forster I. Those cryptic drawings sparked curiosity and speculations for centuries, but only now has technology armed researchers with proof: the secret passages do exist.
Military Maneuvers and Personal Passageways
The purpose of these tunnels? On one hand, they likely had a strategic, military role—after all, you don’t put that much effort into digging under a castle just for kicks. On the other, some of the tunnels had deeply personal and symbolic value. One tunnel, for instance, connected the castle to the Basilica of Santa Maria delle Grazie—home to Leonardo’s celebrated fresco, The Last Supper. This hidden link would have allowed fast access between the castle and the Sforza family tombs inside the church, weaving together secular power with spiritual sanctuary. In other words, the tunnels reveal not just battles and defense, but intimate aspects of the Sforza dynasty’s daily and spiritual life.
How Science Brought Shadows into the Light
The confirmation of Sforza Castle’s tunnels wouldn’t have been possible without a serious boost from 21st-century tech. Ground-penetrating radar and laser scanning have enabled researchers to map out these hidden spaces, uncover new unknown passages, and offer fresh insight into historic structures. Francesca Biolo, a researcher at Politecnico di Milano, emphasized the importance of these technologies, noting how they open up previously inaccessible spaces for exploration and form the basis for future studies on secret passageways.
These cutting-edge tools let us not only visualize what’s left of old structures but also rediscover elements lost to history. Integrating this data into digital models opens exciting new doors for historical and archaeological research. It’s a vivid reminder that technology now lets us look at the past not as a static museum exhibit, but as a living, evolving story.
From Digital Twins to Augmented Reality: The Future of Exploring Sforza Castle
Experts now plan to create a “digital twin” of Sforza Castle—a virtual replica that reconstructs not just its present-day appearance, but the evolution of the castle across the centuries. Franco Guzzetti, professor of geomatics at Politecnico di Milano, explained that the digital model will be enriched with historical elements, presenting a comprehensive picture of all the transformations the castle has undergone.
Accompanying this digital revamp may be augmented reality features for museum-goers, letting visitors wander through underground environments and restricted historic areas in immersive ways. Such innovation could totally transform the experience of visiting the castle, offering guests new ways to discover and interact with history. Leonardo’s legacy continues to enchant and surprise, seamlessly blending the brilliance of the past with the technology of today—as if da Vinci himself wouldn’t have found all this thrilling.
Sforza Castle today houses three distinct museums: the Pinacoteca del Castello Sforzesco, the Museum of the Pietà Rondanini, and the Museum of Ancient Art. This underground discovery could significantly boost cultural tourism in Milan. The new insights into the castle and its hidden structures are already catching the attention of scholars and history lovers alike.
The possibility of virtually exploring these tunnels, via digital technology and augmented reality, could energize the tourist scene. Visitors might soon delve into a lesser-known side of Milanese heritage, enriching their cultural adventure. This discovery is a perfect example of how advances in technology can redefine and deepen our interaction with history, making the invisible visible and uncovering new perspectives on cherished heritage sites.
As the digital twin project for Sforza Castle advances, big questions remain: How will these emerging technologies reshape our understanding and experience of cultural heritage in the years ahead? And are these tunnels just the tip of the iceberg of what lies hidden beneath our feet?
Jessica Roux is a journalist specializing in economic communication, with a hybrid background in writing, editorial strategy, and project management. A graduate of Sciences Po, she untangles the shifting dynamics of information and the big trends shaping today’s media and economy.
