'Bella Firenze' was a commonplace already in the renaissance, especially among Florentines themselves.
One citation may stand for all, Leonardo Bruni's famous 'Panegyric to the City of Florence' (Laudatio Florentinae Urbis) of about 1402, which was adopted almost as an official city manifesto. 'Florence is of such a nature that a more distinguished or more splendid city cannot be found on the entire earth...Just as [Florentine] citizens surpass all other men by a great deal in their natural genius, prudence, elegance, and magnificance, so the city of Florence has surpassed all other cities in its prudent site and its splendor, architecture, and cleanliness...By Jove, everything here is striking and decorated with outstanding beauty'.*
Bruni's admonition to vistors may serve as our own motto: 'Let [a visitor] come here and walk though the city. But don't let him pass through like a temporary guest or a hurrying tourist . Rather, he should pause, poke around, and try to understand what he is seeing'.
* Quoted from the full translation by Benjamin G. Kohl (including his spelling), in 'The Earthly Republic: Italian Humanists on Government and Society', edited by Benjamin G. Kohl and Ronald G. Witt with Elizabeth B. Welles (University of Pennsylvania Press, 1978), pp. 135-175.
Where better first to 'pause, poke around, and try to understand' than the cathedral of Florence, Santa Maria del Fiore?