In 1418, Filippo Brunelleschi was tasked with building the largest dome ever seen at the time. He had no formal architecture training. Yet experts still don't fully understand the brilliant methods he used in contructing the dome, which tops the Santa Maria del Fiore cathedral in Florence, Italy. Read more about the dome in National Geographic magazine online: ngm.nationalgeographic.com/2014/02/il-duomo/mueller-text PRODUCER, EDITOR, AND WRITER: Hans Weise ART DIRECTOR: Fernando G. Baptista ART AND ANIMATION: Fernando G. Baptista and Matthew Twombly MAP AND TYPOGRAPHY: Lauren E. James ADDITIONAL WRITING: Jason Orfanon NARRATOR: Paula Rich RESEARCH: Fanna Gebreyesus and Elizabeth Snodgrass SPECIAL THANKS: Riccardo Dalla Negra, Massimo Ricci, and Francesco Gurrieri