Central Florence's northernmost square is framed by a pair of gates: the Porta San Gallo, once the busiest gate in the medieval walls and a slightly ridiculous triumphal arch, erected in 1738, to celebrate the arrival of the Lorraine dukes in Tuscany.
The piazza took its current elliptical form with its fountain when usual suspect Giuseppe Poggi re-arranged it after the walls went down. It went through many name changes in its history, before the powers that be decided on the current Piazza della Libertà. The square is busiest in winter, when its parterres are flooded to form an ice skating rink.
Image by MarcusObal, Creative Commons License