Il Cattedrale di Santa Maria del Fiore in Florence is a masterpiece church. I read a story in John Kay’s book Obliquity  about the history of the dome that I find worth sharing with you here in case you don’t already know it.
Filippo Brunelleschi was one of the architects competing for the commision to build the Duomo, i.e, the dome. The way he won the commision was as follows. He challenged his competitors to stand an egg in an upright position on a piece of marble. The rivals simply failed. Then Brunelleschi tapped the shell on the marble, the egg broke, and he stood the egg by placing the broken end at the bottom. The rivals got upset. They more or less said something along the lines ‘this is cheating, we could have done the same if we knew we could do such a thing’. That’s when Brunelleschi was ready to score his “goal”. Anyone could build the dome he had in mind once they had seen his solution. What a presentation to win the commission. For more accomplishments of Filippo, see 
 Obliquity, Chapter 6 by John Kay
 Filippo Brunelleschi (Wikipedia)