The Nature Reserve covers an area of 1,604 hectares and its altitude goes from about 940 to 1,221 meters. The most characteristic aspect of the area is given by the presence of two calcareous mountains dominating it, Sasso di Simone and Simoncello. They are characterized at the summit by small "plateaus" surrounded by rocky walls or very steep sides. In a relatively small area you will find very diversified environments, from rocky habitats (calcareous walls and screes at their foot) to gullies, woods, grazing lands, from meadows to shrubby grasslands and bush formations. The woods are mainly dominated by Turkey oak and hornbeam, a rare example of Mediterranean-mountain forest. The Reserve has been established to protect the floristic, vegetational, and landscape features characterizing it, but it is also interesting from a zoological point of view.