This guided tour lets you discover an unexpected side of Orvieto, the underground town. Built on volcanic rock, such as tufa and Pozzolana, the town has a large network of caves which have extended the already dug out underground caves from the Etruscan era. During the visit to the caves (there are more than 1,000!), you will see medieval funereal niches, the foundations and the millstones of an oil press from the 14 C and wells dug out in the 6 C BC.