Florence is where the Renaissance worked out how to build, and the cathedral group is the proof standing in one square. Two and a half kilometres, best early — the piazza fills fast, and the marble is at its best in low morning light before the heat lands.
Start at the Battistero, the oldest building in the centre and the one Dante was baptised in, then circle to Ghiberti's gilded east doors. The cathedral comes next: walk its banded marble flank to feel the length before you face Brunelleschi's cupola, the dome raised without a frame because no one yet knew how to span it. Climb something if you can — Giotto's campanile is the contrarian's choice, because from there you look across at the dome instead of standing on it.
Then the spine: down Via dei Calzaiuoli, the wide street the Medici cut as the city's axis, to Orsanmichele, a grain hall turned church with the guilds' statues in its outer niches. Walk on to Piazza della Signoria a minute south — where the next walk begins, and the trams and buses are close.
