The dome that crowns Florence’s great cathedral of Santa Maria del Fiore — the Duomo — is a masterpiece of Renaissance ingenuity and an enduring source of mystery. Still the largest masonry dome on earth after more than six centuries, it is taller than the Statue of Liberty and weighs as much as an average cruise ship. Historians and engineers have long debated how its architect, Filippo Brunelleschi, kept the dome perfectly aligned and symmetrical as the sides rose and converged toward the center, 40 stories above the cathedral floor. At this terrifying height, his laborers toiled without safety nets, applying novel, untried methods on a truly monumental scale. More than four million bricks could collapse at any moment — and we still don’t understand how Brunelleschi prevented it. To test the latest theories, a team of U.S. bricklayers will help build an experimental “mini-Duomo” using period techniques. “Great Cathedral Mystery” will also highlight exciting new discoveries, including traces of Brunelleschi’s workshop, complete with his own prototype mini-dome model, and will explore the restless, innovative mind of this Renaissance master.