Piazza del Campo is the principal public space of the historic center of Siena, Tuscany, Italy and is regarded as one of Europe‘s greatest medieval squares. It is renowned worldwide for its beauty and architectural integrity. The Palazzo Pubblico and its Torre del Mangia, as well as various palazzi signorili surround the shell-shaped piazza. At the northwest edge is the Fonte Gaia.
excerpt from Wikipedia http://en.wikipedia.org/wiki/Piazza_del_Campo