From the World Heritage inscription:
Built on the site of an Etruscan settlement, Florence, the symbol of the Renaissance, rose to economic and cultural pre-eminence under the Medici in the 15th and 16th centuries. Its 600 years of extraordinary artistic activity can be seen above all in the 13th-century cathedral (Santa Maria del Fiore), the Church of Santa Croce, the Uffizi and the Pitti Palace, the work of great masters such as Giotto, Brunelleschi, Botticelli and Michelangelo.
I didn’t know a lot about Florence before I arrived, other than it was the seat of the Renaissance. I found it to be my favorite city in Italy. The single most recognizable feature of the skyline is the Florence Cathedral. It was at the time of its construction the largest dome in the world. I took this photo from across the river using a zoom lens.
View my complete list of UNESCO World Heritage Sites.