The Berber name means the wall, a reference to the fortress walls that originally enclosed the city.
A wall was built enclosing the city between 1556-1605 with three gateways.
Orvieto is also home to Etruscan ruins and the remnants of a wall that enclosed the city more than 2000 years ago.
The pattern repeated itself when the Swedish forces managed to enclose the city and cut off the supply.
It is also still possible today to see remains of some of the fortifications that used to enclose the city.
The biosphere that enclosed the city was big enough to have clouds floating in its atmosphere.
It is the largest - today 100ft high, but originally 150ft - and sole survivor of 80 similar constructions that once enclosed the city.
The first set of walls to enclose the city were built in the 13th century.
It encloses the city of Passau geographically from two sides.
This river nearly encloses the city, and has wide white beaches.
