The "Magredi di Firmano" site covers a surface of 57,44 hectares and occupies a portion of the alluvial terraces, the gorge and the Natisone middle fluvial course. This site includes a river stretch between Cividale and Premariacco where waters have shaped the alluvial riverbed. The floor is gravelly with blocks of conglomerates and, on the slopes, a very mesic wood develops with interesting natural characteristics. This site is in large part inserted in a rural landscape and its management on the plain is quite variable.