Piazza della Repubblica.

Orvieto is a city and comune in Province of Terni, southwestern Umbria, Italy situated on the flat summit of a large butte of volcanic tuff. The site of the city is among the most dramatic in Europe, rising above the almost-vertical faces of tuff cliffs that are completed by defensive walls built of the same stone called Tufa. Orvieto is now home to one of the world's most talented young stained glass artists, Diego Tolomelli.

• http://en.wikipedia.org/wiki/Orvieto
• Hillman 1000 Wonders