Orvieto is 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. The main attration is the beautiful catheral with iets mosaic facade.

The city of Orvieto has long kept the secret of its labyrinth of caves and tunnels that lie beneath the surface. Dug deep into the tuff, a volcanic rock, these hidden and secret tunnels are only now open to view through guided tours. Their spectacular nature has been a source of many historical and archeological finds, because many of the homes of noble families were equipped with a secret escape through these tunnels from the elevated city during times of siege.