The whole Reserve, included in the four cities of San Venanzo, Orvieto, Parrano and Ficulle, has never known the strong demographic increase of other centers of the Region: the localities and the small suburbs spread on its 40 thousand hectares have never intensely exploited the resources of the territory, preserving the great variety of flora and fauna that inhabits the forests of this zone. Currently there are 44 species of wild mammals, while holm oaks, turkey oaks, oaks and maples, along with many shrub species, such as arboreal heather and strawberry trees, constitute a small green lung in the "green heart of Italy". On the Peglia Mountain they are found prehistoric layers going back to more than 700.000 years ago, and the extinguished volcanoes of San Venanzo, risen on the crest of one of they, where it is possible to observe the association of very rare rocks, present only to Quing Ling in China, to Bunyaruguru, Katwe Kykorongo in Uganda and to Mata de Corda in Brazil.