The text that helps you understand that "kumpola" refers to the dome construction on Florence's Grand Cathedral is:
"construction on Florence's Grand cathedral began in 1296 over 100 years later. However, the structure remained unfinished with an enormous hole in the roof. The designers had intended to top the cathedral with the world's largest dome."
Additionally, the phrase "no one knew how to create such a massive coupla without large numbers and support systems" provides context about the challenges faced in completing the dome.