And recently, a team of researchers discovered one of those surprises—one drawing of a castle tunnel from a 1400s-era castle. See, the drawing was of Sforza Castle, and it included depictions of ...

Now, scientists have uncovered a hidden feature underneath a medieval castle in Milan, Italy, that researchers once could only speculate about based on a sketch of Leonardo’s from around 1495 ...

Sketches in Leonardo da Vinci's Codex Forster I appear to show tunnels leading from the castle. Ground-penetrating radar ...