Built on a volcanic tuff plateau, Orvieto has overlooked the valley since the fourth century. Above the houses, churches and palazzi stands visible from everywhere, its extraordinary, massive Duomo the foundation stone of which was laid in 1290 by Pope Nicholas IV and dedicated to celebrating the assumption of the Virgin. Many well-known artists came, such as Lorenzo Maitani and Andrea Pisano. In the chapel of San Brizio, after the first work by Fra Angelico, Luca Signorelli painted The Last Judgement, a high point of Renaissance painting.
St. Patrick's Well, built at the behest of Pope Clement VII in 1527, is an interesting landmark today. It was built to ensure the water supply to the fortress which today is home to the public gardens. The Necropolis of Crocefisso di Tufo instead, conserves important ancient remains of Etruscan tombs.