The territory included within this area comprises the right side (hydrographic perspective) of the Matteraia stream, which is a tributary of the river Marecchia, between the upper Tiberina Valley and the upper Marecchia Valley. The most important groups can be found in the Valbuia and in the Fossa Grande, where it is possible to see trees over 10 meters high. The protected area also includes an important mixed forest situated at the foot of the Zucca Mountain (1,623 meters), which is characterized by the significant presence of many European Yews (Taxus Baccata), a very localized and rare species in Tuscany.