A walk along the route of the road San Francesco is the best way to learn about a valuable nature reserve consists of the Stain of Gattaceca and the Reserve del Barco.
The reserve covers 997 hectares, between the valley of the River Tiber and the Monti Cornicolani with vast grazing areas and agricultural use. The area is protected for both the botanical value of its forest fragments that for intense karst that occurs with caves, sinkholes, "sventatori" and sinkholes. The Reserve, which extend the olive groves from which we get the precious oil of Sabina, is home to private farms and Experimental Institute of Tor Mancina, which deals with livestock, plant pathology and experimental zoology.
The journey of faith unites the Franciscan monasteries of the Holy Valley of Rieti with St. Peter's Basilica in Rome. This is a deviation from the ancient Via Francigena crossed by many pilgrims who come to visit to Assisi, the monasteries in Rieti and continue to Rome. The stretch present in Monterotondo through the nature reserve and touches the heights of Grottamarozza, an important medieval settlement of which there are important architectural remains.