Everyone climbs to Boboli; the garden next door is better and half as crowded, and the way up to it is the quietest steep lane in the centre. This is the back climb out of Florence, and the wisteria at the top of it.
Under three kilometres, best on an afternoon in spring. From the south end of the Ponte Vecchio, turn up Costa San Giorgio — a walled lane of garden doors and ochre plaster, Galileo's house at number 19, the noise of the bridge gone within a minute. The lane ends at Porta San Giorgio, the oldest gate left in the city, St George still riding over the arch.
Through it and into the Giardino Bardini. Come in April and the long pergola is a hanging tunnel of wisteria — go even if you have to time the whole trip around it. The terrace below gives you the duomo and the tower over the roofs, with room to breathe.
Leave by the lower gate and drop to Porta San Niccolò by the river. Bus 12 home, or walk the Arno.