Hidden Passages Matching Da Vinci's Sketches Discovered at Milan's Sforza Castle

Hidden underground passages have been discovered at the Sforza Castle in Milan, Italy, coinciding with sketches made by Leonardo da Vinci in 1495. The passages, part of an ancient military defense system, were found during a detailed study of the castle's subterranean spaces using laser scanning, GPS, 3D ground-penetrating radar, and photogrammetry. The team, led by architectural historian Francesca Biolo, identified rooms on a second subterranean level and an additional passage running parallel to a known one. These newly discovered passages align with da Vinci's sketches, revealing his extensive knowledge of military structures and defensive systems. While da Vinci was contracted to beautify the castle in the late 15th century, the extent of his involvement in the fortress's construction remains uncertain. Excavation is not currently feasible, but researchers believe more hidden structures may exist within the castle.