The dome of Basilica di Santa Maria del Fiore is the architectural and engineering marvel of Filippo Brunelleschi. It consists of 37,000 tons of construction materials, including over four million bricks in a herringbone pattern. On top of the lantern is a bronze ball. This was made by Andrea del Verrocchio and his apprentice, Leonardo da Vinci. From the dome’s initial design until its completion in 1469 required 173 years of labor.