Orvieto lies on top of a hill of tuff rocks where nature itself took care of constructing most of the city walls. From its plateau of tuff the visitor enjoys a wonderful view on the surrounding farmland, vineyards and on the river Tiber. Orvieto has two souls which cohabit in perfect harmony and make it at the same time superb and mysterious. It is namely on the one hand a classic city with its very beautiful Cathedral and the frescos of Signorelli, reflecting its medieval and papal character, and on the other it is also a subterranean city, where by walking inside grottoes, small tunnels and labyrinths one discovers, like in a secret plot, a city under the city.
Sunny Orvieto is famous in the first place for its Duomo di Santa Maria Assunta, a jewel of gothic art which surprises and enchants the visitor. This is not surprising since it was built by the popes in competition with the Cathedral of Siena. Orvieto is famous in the second place for the Pozzo di San Patrizio, the symbol of the underground city, a masterpiece of hydraulic engineering built in the year 1527 by the Pope in order to guarantee to the city a sufficient supply of water in case of prolonged enemy sieges.