Building a monumental dome without the use of external iron chains or traditional centering was the enormous challenge faced by Filippo Brunelleschi at the Cathedral of Santa Maria del Fiore in Florence. To demonstrate the feasibility of his proposal and to guide the construction, he relied on a large-scale wooden model that played a fundamental role in studying proportions, the interlocking of ribs, and the innovative arrangement of bricks using the "a spina pesce" (herringbone) system. As an essential technical tool, this model — which is still on display at the Museo dell'Opera del Duomo in Florence — guided the master builders throughout the construction, establishing itself as a seminal example of the value of models in architectural planning, constructive communication, and experimentation.