The medieval village Sorano dates back to the Etruscan times. Like many villages in this area, Sorana is on the top of hills, made of volcanic tuff stone. In the rocks under the village are many man made caves visible. Cutting them into the soft tuff rock is not difficult and was already done in ancient times. Many caves contain small niches for pigeons to make nests and create guano as fertilizer for the farmers fields. This way of producing guano was already known by the Egyptian pharaoes and is still in use today in the valleys of Cappadocia (Turkey). The Italians call these niches "colombaio" according to the Latin word for pigeon: colomba. Later this word changed its meaning and today its used for the special Italian graveyards in walls. The niches of the graves have a shape very similar to the niches for pigeons.