Construction on Santa Maria del Fiore’s cathedral began in 1296 to show off the status of Florence as one of Europe’s economic and cultural capitals. Still, decades later, no one seemed to have any idea of how to build a dome nearly 150 feet across, especially as it would have to start 180 feet above the ground, atop the existing walls. So in 1418 the Florentine fathers decided to hold a contest for the ideal dome design, with a prize of 200 gold florins--and perhaps even eternal glory--for the winner. Boy did they get some interesting suggestions: one guy proposed to support the dome with an enormous pillar rising in the center of the church. Another suggested building it out of “sponge-stone” (a porous volcanic rock) to minimize its weight.
