Paris had Haussmann, Rome had Valadier, Florence had Poggi. These men changed the looks of their respective cities.
I spend a lot of time on the Viale dei Colli, the gorgeous drive through the hills to the south of the city of Florence. This is where you will find Piazzale Michelangelo (designed by Poggi) as well as the Rose Garden, San Miniato al Monte, Forte Belvedere and so much more. Poggi linked all of these sites along his magnificent Viale, which was then covered with expensive villas by wealthy citizens.
Someone should write a book in English about this gorgeous Viale and its fascinating history!