Le Murate is the best thing Florence has done with a building it should have been ashamed of. A convent that walled its nuns in for four centuries, then a prison until 1985, it is now a courtyard of café tables, flats and studios — and you sit drinking coffee where the cell doors were.
Start in the cortile at the Caffè Letterario Le Murate, reading the plaques that quote what prisoners scratched into the walls. Then walk it off west along Via Ghibellina and into the side lanes — frame-makers, washing on the line, the residential Florence that sells you nothing. The middle of the walk is a climb you don't expect: the Biblioteca delle Oblate, a convent-turned-library whose top-floor café terrace frames Brunelleschi's dome better than any paid viewpoint, and lets anyone up for the price of a coffee.
Down past Casa Buonarroti, Michelangelo's family shrine, and into Piazza Santa Croce from its quiet back corner — the side the tour groups never use. Stand at the edge, watch the square work, and take the small electric bus back into the centre.