Numerous secret passages have been discovered under Milan’s Sforza Castle, some of which were immortalised in drawings by Leonardo da Vinci.
Built in the 15th century, Sforza Castle has been extensively renovated and rebuilt over the centuries, earning it the title of one of the largest citadels in Europe. Today it houses several of the city’s museums and art collections.
Suspicions about secret passageways date as far back as the 1490s when it was thought that the Duke of Milan, Ludovico Sforza – or il Moro – had a tunnel built to reach the nearby Basilica di Santa Maria delle Grazie, where his wife Beatrice d’Este was buried following her death in childbirth.
Leonardo da Vinci, who was employed by the duke to decorate some of the castle’s rooms, had created drawings of this passageway and others thought to have been built for use by the military in case of attack.
The existence of these passageways has long been the subject of legends and speculations. However, with the use of technology their presence has now been confirmed.
As part of a PhD thesis, the Polytechnic University of Milan worked in collaboration with the Sforza Castle and instrumentation company Codevintec to uncover the presence of numerous passages in an area once covered by the ‘Ghirlanda’ or outer wall, as shown in da Vinci’s drawings.
The investigation used advanced technologies, including ground-penetrating radars (GPRs) and laser scanners, to accurately map and document the castle’s sub-surface and underground structures. These instruments were able to reveal underground cavities and passageways a foot or two beneath the surface.
Franco Guzzetti, professor of geomatics at the Polytechnic University of Milan, said: “The aim is to create a digital twin of the Sforza Castle, a digital model that not only shows the current appearance of the castle, but also allows us to explore the past, by revealing ancient structures that are no longer visible.”
The data was integrated into augmented reality technologies to create virtual paths to allow for the exploration of these underground passages.
This is significant historically, but also has the potential to offer tourists an immersive experience of this aspect of the castle’s history.
Francesca Biolo, a researcher at the university, said: “The GPR technology has added to our 3D model by providing data about well-known but inaccessible spaces, revealing unknown pathways and suggesting ideas for further research into these secret passages.”
Source: E&T
